Termination of the following Term Rewriting System could not be shown:

Context-sensitive rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zeros)
and(tt, X) → X
length(nil) → 0
length(cons(N, L)) → s(length(L))

The replacement map contains the following entries:

zeros: empty set
cons: {1}
0: empty set
and: {1}
tt: empty set
length: {1}
nil: empty set
s: {1}


CSR
  ↳ CSRInnermostProof

Context-sensitive rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zeros)
and(tt, X) → X
length(nil) → 0
length(cons(N, L)) → s(length(L))

The replacement map contains the following entries:

zeros: empty set
cons: {1}
0: empty set
and: {1}
tt: empty set
length: {1}
nil: empty set
s: {1}

The CSR is orthogonal. By [10] we can switch to innermost.

↳ CSR
  ↳ CSRInnermostProof
CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Context-sensitive rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zeros)
and(tt, X) → X
length(nil) → 0
length(cons(N, L)) → s(length(L))

The replacement map contains the following entries:

zeros: empty set
cons: {1}
0: empty set
and: {1}
tt: empty set
length: {1}
nil: empty set
s: {1}

Innermost Strategy.

Using Improved CS-DPs we result in the following initial Q-CSDP problem.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
QCSDP
          ↳ QCSDependencyGraphProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q-restricted context-sensitive dependency pair problem:
The symbols in {length, s, LENGTH} are replacing on all positions.
For all symbols f in {cons, and, AND} we have µ(f) = {1}.
The symbols in {U} are not replacing on any position.

The ordinary context-sensitive dependency pairs DPo are:

LENGTH(cons(N, L)) → LENGTH(L)

The collapsing dependency pairs are DPc:

AND(tt, X) → X
LENGTH(cons(N, L)) → L


The hidden terms of R are:

zeros

Every hiding context is built from:none

Hence, the new unhiding pairs DPu are :

AND(tt, X) → U(X)
LENGTH(cons(N, L)) → U(L)
U(zeros) → ZEROS

The TRS R consists of the following rules:

zeroscons(0, zeros)
and(tt, X) → X
length(nil) → 0
length(cons(N, L)) → s(length(L))

The set Q consists of the following terms:

zeros
and(tt, x0)
length(nil)
length(cons(x0, x1))


The approximation of the Context-Sensitive Dependency Graph contains 1 SCC with 3 less nodes.


↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
        ↳ QCSDP
          ↳ QCSDependencyGraphProof
QCSDP
              ↳ ConvertedToQDPProblemProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q-restricted context-sensitive dependency pair problem:
The symbols in {length, s, LENGTH} are replacing on all positions.
For all symbols f in {cons, and} we have µ(f) = {1}.

The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(L)

The TRS R consists of the following rules:

zeroscons(0, zeros)
and(tt, X) → X
length(nil) → 0
length(cons(N, L)) → s(length(L))

The set Q consists of the following terms:

zeros
and(tt, x0)
length(nil)
length(cons(x0, x1))


Converted QDP Problem, but could not keep Q or minimality.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
        ↳ QCSDP
          ↳ QCSDependencyGraphProof
            ↳ QCSDP
              ↳ ConvertedToQDPProblemProof
QDP
                  ↳ RuleRemovalProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(L)

The TRS R consists of the following rules:

zeroscons(0, zeros)
and(tt, X) → X
length(nil) → 0
length(cons(N, L)) → s(length(L))

Q is empty.
We have to consider all (P,Q,R)-chains.
By using the rule removal processor [15] with the following polynomial ordering [25], at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented.

Strictly oriented rules of the TRS R:

and(tt, X) → X
length(nil) → 0

Used ordering: POLO with Polynomial interpretation [25]:

POL(0) = 0   
POL(LENGTH(x1)) = 2·x1   
POL(and(x1, x2)) = 1 + 2·x1 + x2   
POL(cons(x1, x2)) = 2·x1 + 2·x2   
POL(length(x1)) = 2·x1   
POL(nil) = 1   
POL(s(x1)) = 2·x1   
POL(tt) = 2   
POL(zeros) = 0   



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
        ↳ QCSDP
          ↳ QCSDependencyGraphProof
            ↳ QCSDP
              ↳ ConvertedToQDPProblemProof
                ↳ QDP
                  ↳ RuleRemovalProof
QDP
                      ↳ NonTerminationProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(L)

The TRS R consists of the following rules:

zeroscons(0, zeros)
length(cons(N, L)) → s(length(L))

Q is empty.
We have to consider all (P,Q,R)-chains.
We used the non-termination processor [17] to show that the DP problem is infinite.
Found a loop by narrowing to the left:

The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(L)

The TRS R consists of the following rules:

zeroscons(0, zeros)
length(cons(N, L)) → s(length(L))


s = LENGTH(zeros) evaluates to t =LENGTH(zeros)

Thus s starts an infinite chain as s semiunifies with t with the following substitutions:




Rewriting sequence

LENGTH(zeros)LENGTH(cons(0, zeros))
with rule zeroscons(0, zeros) at position [0] and matcher [ ]

LENGTH(cons(0, zeros))LENGTH(zeros)
with rule LENGTH(cons(N, L)) → LENGTH(L)

Now applying the matcher to the start term leads to a term which is equal to the last term in the rewriting sequence


All these steps are and every following step will be a correct step w.r.t to Q.




We applied the Zantema transformation [34] to transform the context-sensitive TRS to a usual TRS.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
QTRS
          ↳ RRRPoloQTRSProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
and(tt, X) → a(X)
length(nil) → 0
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.

The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
and(tt, X) → a(X)
length(nil) → 0
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.
The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

and(tt, X) → a(X)
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(a(x1)) = x1   
POL(and(x1, x2)) = x1 + 2·x2   
POL(cons(x1, x2)) = 2·x1 + 2·x2   
POL(length(x1)) = 2·x1   
POL(nil) = 0   
POL(s(x1)) = 2·x1   
POL(tt) = 1   
POL(zeros) = 0   
POL(zerosInact) = 0   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
QTRS
              ↳ RRRPoloQTRSProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(nil) → 0
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.

The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(nil) → 0
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.
The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

length(nil) → 0
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(a(x1)) = x1   
POL(cons(x1, x2)) = 2·x1 + 2·x2   
POL(length(x1)) = 2·x1   
POL(nil) = 2   
POL(s(x1)) = 2·x1   
POL(zeros) = 0   
POL(zerosInact) = 0   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
QTRS
                  ↳ RRRPoloQTRSProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.

The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.
The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

zeroszerosInact
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(a(x1)) = 2·x1   
POL(cons(x1, x2)) = x1 + 2·x2   
POL(length(x1)) = 2·x1   
POL(s(x1)) = x1   
POL(zeros) = 2   
POL(zerosInact) = 1   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
QTRS
                      ↳ RRRPoloQTRSProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(x) → x
a(zerosInact) → zeros

Q is empty.

The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(x) → x
a(zerosInact) → zeros

Q is empty.
The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

a(x) → x
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(a(x1)) = 1 + x1   
POL(cons(x1, x2)) = 1 + 2·x1 + x2   
POL(length(x1)) = x1   
POL(s(x1)) = x1   
POL(zeros) = 1   
POL(zerosInact) = 0   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
QTRS
                          ↳ Overlay + Local Confluence
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(zerosInact) → zeros

Q is empty.

The TRS is overlay and locally confluent. By [19] we can switch to innermost.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
QTRS
                              ↳ DependencyPairsProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(zerosInact) → zeros

The set Q consists of the following terms:

zeros
length(cons(x0, x1))
a(zerosInact)


Using Dependency Pairs [1,15] we result in the following initial DP problem:
Q DP problem:
The TRS P consists of the following rules:

A(zerosInact) → ZEROS
LENGTH(cons(N, L)) → A(L)
LENGTH(cons(N, L)) → LENGTH(a(L))

The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(zerosInact) → zeros

The set Q consists of the following terms:

zeros
length(cons(x0, x1))
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
QDP
                                  ↳ DependencyGraphProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

A(zerosInact) → ZEROS
LENGTH(cons(N, L)) → A(L)
LENGTH(cons(N, L)) → LENGTH(a(L))

The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(zerosInact) → zeros

The set Q consists of the following terms:

zeros
length(cons(x0, x1))
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 1 SCC with 2 less nodes.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
QDP
                                      ↳ UsableRulesProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(a(L))

The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(zerosInact) → zeros

The set Q consists of the following terms:

zeros
length(cons(x0, x1))
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
QDP
                                          ↳ QReductionProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(a(L))

The TRS R consists of the following rules:

a(zerosInact) → zeros
zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros
length(cons(x0, x1))
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

length(cons(x0, x1))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
QDP
                                              ↳ Narrowing
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(a(L))

The TRS R consists of the following rules:

a(zerosInact) → zeros
zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
By narrowing [15] the rule LENGTH(cons(N, L)) → LENGTH(a(L)) at position [0] we obtained the following new rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(zeros)



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
QDP
                                                  ↳ UsableRulesProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(zeros)

The TRS R consists of the following rules:

a(zerosInact) → zeros
zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
QDP
                                                      ↳ QReductionProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(zeros)

The TRS R consists of the following rules:

zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

a(zerosInact)



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
                                                    ↳ QDP
                                                      ↳ QReductionProof
QDP
                                                          ↳ Rewriting
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(zeros)

The TRS R consists of the following rules:

zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros

We have to consider all minimal (P,Q,R)-chains.
By rewriting [15] the rule LENGTH(cons(y0, zerosInact)) → LENGTH(zeros) at position [0] we obtained the following new rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(cons(0, zerosInact))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
                                                    ↳ QDP
                                                      ↳ QReductionProof
                                                        ↳ QDP
                                                          ↳ Rewriting
QDP
                                                              ↳ UsableRulesProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(cons(0, zerosInact))

The TRS R consists of the following rules:

zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
                                                    ↳ QDP
                                                      ↳ QReductionProof
                                                        ↳ QDP
                                                          ↳ Rewriting
                                                            ↳ QDP
                                                              ↳ UsableRulesProof
QDP
                                                                  ↳ QReductionProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(cons(0, zerosInact))

R is empty.
The set Q consists of the following terms:

zeros

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

zeros



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
                                                    ↳ QDP
                                                      ↳ QReductionProof
                                                        ↳ QDP
                                                          ↳ Rewriting
                                                            ↳ QDP
                                                              ↳ UsableRulesProof
                                                                ↳ QDP
                                                                  ↳ QReductionProof
QDP
                                                                      ↳ Instantiation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(cons(0, zerosInact))

R is empty.
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
By instantiating [15] the rule LENGTH(cons(y0, zerosInact)) → LENGTH(cons(0, zerosInact)) we obtained the following new rules:

LENGTH(cons(0, zerosInact)) → LENGTH(cons(0, zerosInact))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
                                                    ↳ QDP
                                                      ↳ QReductionProof
                                                        ↳ QDP
                                                          ↳ Rewriting
                                                            ↳ QDP
                                                              ↳ UsableRulesProof
                                                                ↳ QDP
                                                                  ↳ QReductionProof
                                                                    ↳ QDP
                                                                      ↳ Instantiation
QDP
                                                                          ↳ NonTerminationProof
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(0, zerosInact)) → LENGTH(cons(0, zerosInact))

R is empty.
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
We used the non-termination processor [17] to show that the DP problem is infinite.
Found a loop by semiunifying a rule from P directly.

The TRS P consists of the following rules:

LENGTH(cons(0, zerosInact)) → LENGTH(cons(0, zerosInact))

The TRS R consists of the following rules:none


s = LENGTH(cons(0, zerosInact)) evaluates to t =LENGTH(cons(0, zerosInact))

Thus s starts an infinite chain as s semiunifies with t with the following substitutions:




Rewriting sequence

The DP semiunifies directly so there is only one rewrite step from LENGTH(cons(0, zerosInact)) to LENGTH(cons(0, zerosInact)).




We applied the Innermost Giesl Middeldorp transformation [10] to transform the context-sensitive TRS to a usual TRS.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
QTRS
          ↳ RRRPoloQTRSProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(and(tt, X)) → mark(X)
active(length(nil)) → mark(0)
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
mark(and(x1, x2)) → active(and(mark(x1), x2))
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(tt) → active(tt)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(nil) → active(nil)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))


The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(and(tt, X)) → mark(X)
active(length(nil)) → mark(0)
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
mark(and(x1, x2)) → active(and(mark(x1), x2))
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(tt) → active(tt)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(nil) → active(nil)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

active(and(tt, X)) → mark(X)
active(length(nil)) → mark(0)
mark(tt) → active(tt)
mark(nil) → active(nil)
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(active(x1)) = x1   
POL(and(x1, x2)) = x1 + 2·x2   
POL(cons(x1, x2)) = x1 + 2·x2   
POL(length(x1)) = 2·x1   
POL(mark(x1)) = 2·x1   
POL(nil) = 1   
POL(s(x1)) = x1   
POL(tt) = 1   
POL(zeros) = 0   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
QTRS
              ↳ RRRPoloQTRSProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
mark(and(x1, x2)) → active(and(mark(x1), x2))
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))


The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
mark(and(x1, x2)) → active(and(mark(x1), x2))
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

mark(and(x1, x2)) → active(and(mark(x1), x2))
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(active(x1)) = x1   
POL(and(x1, x2)) = 2 + 2·x1 + x2   
POL(cons(x1, x2)) = 2·x1 + 2·x2   
POL(length(x1)) = x1   
POL(mark(x1)) = 2·x1   
POL(s(x1)) = x1   
POL(zeros) = 0   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
QTRS
                  ↳ DependencyPairsProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))


Using Dependency Pairs [1,15] we result in the following initial DP problem:
Q DP problem:
The TRS P consists of the following rules:

ACTIVE(length(cons(N, L))) → S(length(L))
CONS(mark(x1), x2) → CONS(x1, x2)
S(mark(x1)) → S(x1)
S(active(x1)) → S(x1)
MARK(s(x1)) → S(mark(x1))
MARK(cons(x1, x2)) → CONS(mark(x1), x2)
MARK(s(x1)) → MARK(x1)
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(cons(x1, x2)) → ACTIVE(cons(mark(x1), x2))
MARK(cons(x1, x2)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))
ACTIVE(length(cons(N, L))) → LENGTH(L)
MARK(length(x1)) → MARK(x1)
AND(mark(x1), x2) → AND(x1, x2)
MARK(s(x1)) → ACTIVE(s(mark(x1)))
MARK(zeros) → ACTIVE(zeros)
MARK(length(x1)) → LENGTH(mark(x1))
ACTIVE(zeros) → MARK(cons(0, zeros))
MARK(0) → ACTIVE(0)
ACTIVE(zeros) → CONS(0, zeros)
LENGTH(mark(x1)) → LENGTH(x1)
CONS(active(x1), x2) → CONS(x1, x2)
AND(active(x1), x2) → AND(x1, x2)
LENGTH(active(x1)) → LENGTH(x1)

The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
QDP
                      ↳ DependencyGraphProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

ACTIVE(length(cons(N, L))) → S(length(L))
CONS(mark(x1), x2) → CONS(x1, x2)
S(mark(x1)) → S(x1)
S(active(x1)) → S(x1)
MARK(s(x1)) → S(mark(x1))
MARK(cons(x1, x2)) → CONS(mark(x1), x2)
MARK(s(x1)) → MARK(x1)
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(cons(x1, x2)) → ACTIVE(cons(mark(x1), x2))
MARK(cons(x1, x2)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))
ACTIVE(length(cons(N, L))) → LENGTH(L)
MARK(length(x1)) → MARK(x1)
AND(mark(x1), x2) → AND(x1, x2)
MARK(s(x1)) → ACTIVE(s(mark(x1)))
MARK(zeros) → ACTIVE(zeros)
MARK(length(x1)) → LENGTH(mark(x1))
ACTIVE(zeros) → MARK(cons(0, zeros))
MARK(0) → ACTIVE(0)
ACTIVE(zeros) → CONS(0, zeros)
LENGTH(mark(x1)) → LENGTH(x1)
CONS(active(x1), x2) → CONS(x1, x2)
AND(active(x1), x2) → AND(x1, x2)
LENGTH(active(x1)) → LENGTH(x1)

The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 5 SCCs with 7 less nodes.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
QDP
                            ↳ UsableRulesProof
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

S(active(x1)) → S(x1)
S(mark(x1)) → S(x1)

The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                            ↳ UsableRulesProof
QDP
                                ↳ QReductionProof
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

S(active(x1)) → S(x1)
S(mark(x1)) → S(x1)

R is empty.
The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

cons(active(x0), x1)
cons(mark(x0), x1)
and(active(x0), x1)
and(mark(x0), x1)
length(active(x0))
length(mark(x0))
s(active(x0))
s(mark(x0))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
QDP
                                    ↳ QDPSizeChangeProof
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

S(mark(x1)) → S(x1)
S(active(x1)) → S(x1)

R is empty.
The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
mark(nil)
mark(s(x0))

We have to consider all minimal (P,Q,R)-chains.
By using the subterm criterion [20] together with the size-change analysis [32] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
QDP
                            ↳ UsableRulesProof
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(mark(x1)) → LENGTH(x1)
LENGTH(active(x1)) → LENGTH(x1)

The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
QDP
                                ↳ QReductionProof
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(mark(x1)) → LENGTH(x1)
LENGTH(active(x1)) → LENGTH(x1)

R is empty.
The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

cons(active(x0), x1)
cons(mark(x0), x1)
and(active(x0), x1)
and(mark(x0), x1)
length(active(x0))
length(mark(x0))
s(active(x0))
s(mark(x0))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
QDP
                                    ↳ QDPSizeChangeProof
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(mark(x1)) → LENGTH(x1)
LENGTH(active(x1)) → LENGTH(x1)

R is empty.
The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
mark(nil)
mark(s(x0))

We have to consider all minimal (P,Q,R)-chains.
By using the subterm criterion [20] together with the size-change analysis [32] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
QDP
                            ↳ UsableRulesProof
                          ↳ QDP
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

AND(mark(x1), x2) → AND(x1, x2)
AND(active(x1), x2) → AND(x1, x2)

The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
QDP
                                ↳ QReductionProof
                          ↳ QDP
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

AND(mark(x1), x2) → AND(x1, x2)
AND(active(x1), x2) → AND(x1, x2)

R is empty.
The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

cons(active(x0), x1)
cons(mark(x0), x1)
and(active(x0), x1)
and(mark(x0), x1)
length(active(x0))
length(mark(x0))
s(active(x0))
s(mark(x0))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
QDP
                                    ↳ QDPSizeChangeProof
                          ↳ QDP
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

AND(mark(x1), x2) → AND(x1, x2)
AND(active(x1), x2) → AND(x1, x2)

R is empty.
The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
mark(nil)
mark(s(x0))

We have to consider all minimal (P,Q,R)-chains.
By using the subterm criterion [20] together with the size-change analysis [32] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
QDP
                            ↳ UsableRulesProof
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

CONS(mark(x1), x2) → CONS(x1, x2)
CONS(active(x1), x2) → CONS(x1, x2)

The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
QDP
                                ↳ QReductionProof
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

CONS(mark(x1), x2) → CONS(x1, x2)
CONS(active(x1), x2) → CONS(x1, x2)

R is empty.
The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

cons(active(x0), x1)
cons(mark(x0), x1)
and(active(x0), x1)
and(mark(x0), x1)
length(active(x0))
length(mark(x0))
s(active(x0))
s(mark(x0))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
QDP
                                    ↳ QDPSizeChangeProof
                          ↳ QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

CONS(mark(x1), x2) → CONS(x1, x2)
CONS(active(x1), x2) → CONS(x1, x2)

R is empty.
The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
mark(nil)
mark(s(x0))

We have to consider all minimal (P,Q,R)-chains.
By using the subterm criterion [20] together with the size-change analysis [32] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
QDP
                            ↳ UsableRulesProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(x1)) → MARK(x1)
MARK(s(x1)) → MARK(x1)
MARK(s(x1)) → ACTIVE(s(mark(x1)))
MARK(zeros) → ACTIVE(zeros)
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(cons(x1, x2)) → ACTIVE(cons(mark(x1), x2))
ACTIVE(zeros) → MARK(cons(0, zeros))
MARK(cons(x1, x2)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))

The TRS R consists of the following rules:

active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
cons(active(x1), x2) → cons(x1, x2)
cons(mark(x1), x2) → cons(x1, x2)
mark(0) → active(0)
and(active(x1), x2) → and(x1, x2)
and(mark(x1), x2) → and(x1, x2)
mark(length(x1)) → active(length(mark(x1)))
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
mark(s(x1)) → active(s(mark(x1)))
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
QDP
                                ↳ QReductionProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(x1)) → MARK(x1)
MARK(s(x1)) → MARK(x1)
MARK(s(x1)) → ACTIVE(s(mark(x1)))
MARK(zeros) → ACTIVE(zeros)
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(cons(x1, x2)) → ACTIVE(cons(mark(x1), x2))
ACTIVE(zeros) → MARK(cons(0, zeros))
MARK(cons(x1, x2)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
and(active(x0), x1)
and(mark(x0), x1)
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

and(active(x0), x1)
and(mark(x0), x1)



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
QDP
                                    ↳ RuleRemovalProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(x1)) → MARK(x1)
MARK(cons(x1, x2)) → ACTIVE(cons(mark(x1), x2))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(zeros) → ACTIVE(zeros)
MARK(s(x1)) → ACTIVE(s(mark(x1)))
MARK(s(x1)) → MARK(x1)
ACTIVE(zeros) → MARK(cons(0, zeros))
MARK(cons(x1, x2)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
By using the rule removal processor [15] with the following polynomial ordering [25], at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented.
Strictly oriented dependency pairs:

MARK(length(x1)) → MARK(x1)


Used ordering: POLO with Polynomial interpretation [25]:

POL(0) = 0   
POL(ACTIVE(x1)) = x1   
POL(MARK(x1)) = x1   
POL(active(x1)) = x1   
POL(cons(x1, x2)) = 2·x1 + 2·x2   
POL(length(x1)) = 2 + x1   
POL(mark(x1)) = x1   
POL(s(x1)) = x1   
POL(zeros) = 0   



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
QDP
                                        ↳ QDPOrderProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(s(x1)) → MARK(x1)
MARK(s(x1)) → ACTIVE(s(mark(x1)))
MARK(zeros) → ACTIVE(zeros)
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(cons(x1, x2)) → ACTIVE(cons(mark(x1), x2))
ACTIVE(zeros) → MARK(cons(0, zeros))
MARK(cons(x1, x2)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We use the reduction pair processor [15].


The following pairs can be oriented strictly and are deleted.


MARK(zeros) → ACTIVE(zeros)
The remaining pairs can at least be oriented weakly.

MARK(s(x1)) → MARK(x1)
MARK(s(x1)) → ACTIVE(s(mark(x1)))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(cons(x1, x2)) → ACTIVE(cons(mark(x1), x2))
ACTIVE(zeros) → MARK(cons(0, zeros))
MARK(cons(x1, x2)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))
Used ordering: Polynomial interpretation with max and min functions [25]:

POL(0) = 0   
POL(ACTIVE(x1)) = 0   
POL(MARK(x1)) = x1   
POL(active(x1)) = x1   
POL(cons(x1, x2)) = x1   
POL(length(x1)) = 0   
POL(mark(x1)) = x1   
POL(s(x1)) = x1   
POL(zeros) = 1   

The following usable rules [17] were oriented:

length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
QDP
                                            ↳ DependencyGraphProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(cons(x1, x2)) → ACTIVE(cons(mark(x1), x2))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(x1)) → ACTIVE(s(mark(x1)))
MARK(s(x1)) → MARK(x1)
ACTIVE(zeros) → MARK(cons(0, zeros))
MARK(cons(x1, x2)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 1 SCC with 1 less node.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
QDP
                                                ↳ QDPOrderProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(s(x1)) → MARK(x1)
MARK(s(x1)) → ACTIVE(s(mark(x1)))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(cons(x1, x2)) → ACTIVE(cons(mark(x1), x2))
MARK(cons(x1, x2)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We use the reduction pair processor [15].


The following pairs can be oriented strictly and are deleted.


MARK(cons(x1, x2)) → ACTIVE(cons(mark(x1), x2))
MARK(cons(x1, x2)) → MARK(x1)
The remaining pairs can at least be oriented weakly.

MARK(s(x1)) → MARK(x1)
MARK(s(x1)) → ACTIVE(s(mark(x1)))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(length(x1)) → ACTIVE(length(mark(x1)))
Used ordering: Polynomial interpretation with max and min functions [25]:

POL(0) = 0   
POL(ACTIVE(x1)) = 0   
POL(MARK(x1)) = x1   
POL(active(x1)) = x1   
POL(cons(x1, x2)) = 1 + x1   
POL(length(x1)) = 0   
POL(mark(x1)) = x1   
POL(s(x1)) = x1   
POL(zeros) = 0   

The following usable rules [17] were oriented:

length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
QDP
                                                    ↳ QDPOrderProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(x1)) → ACTIVE(s(mark(x1)))
MARK(s(x1)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We use the reduction pair processor [15].


The following pairs can be oriented strictly and are deleted.


MARK(s(x1)) → ACTIVE(s(mark(x1)))
The remaining pairs can at least be oriented weakly.

ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(x1)) → MARK(x1)
MARK(length(x1)) → ACTIVE(length(mark(x1)))
Used ordering: Polynomial interpretation [25]:

POL(0) = 0   
POL(ACTIVE(x1)) = x1   
POL(MARK(x1)) = 1   
POL(active(x1)) = 0   
POL(cons(x1, x2)) = 0   
POL(length(x1)) = 1   
POL(mark(x1)) = 0   
POL(s(x1)) = 0   
POL(zeros) = 0   

The following usable rules [17] were oriented:

length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
QDP
                                                        ↳ Narrowing
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(s(x1)) → MARK(x1)
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(length(x1)) → ACTIVE(length(mark(x1)))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
By narrowing [15] the rule MARK(length(x1)) → ACTIVE(length(mark(x1))) at position [0] we obtained the following new rules:

MARK(length(0)) → ACTIVE(length(active(0)))
MARK(length(length(x0))) → ACTIVE(length(active(length(mark(x0)))))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
MARK(length(zeros)) → ACTIVE(length(active(zeros)))
MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
MARK(length(x0)) → ACTIVE(length(x0))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
QDP
                                                            ↳ Rewriting
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(zeros)) → ACTIVE(length(active(zeros)))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(x1)) → MARK(x1)
MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
MARK(length(0)) → ACTIVE(length(active(0)))
MARK(length(length(x0))) → ACTIVE(length(active(length(mark(x0)))))
MARK(length(x0)) → ACTIVE(length(x0))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
By rewriting [15] the rule MARK(length(0)) → ACTIVE(length(active(0))) at position [0] we obtained the following new rules:

MARK(length(0)) → ACTIVE(length(0))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
QDP
                                                                ↳ DependencyGraphProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(0)) → ACTIVE(length(0))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
MARK(length(zeros)) → ACTIVE(length(active(zeros)))
MARK(s(x1)) → MARK(x1)
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
MARK(length(length(x0))) → ACTIVE(length(active(length(mark(x0)))))
MARK(length(x0)) → ACTIVE(length(x0))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 1 SCC with 1 less node.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
                                                              ↳ QDP
                                                                ↳ DependencyGraphProof
QDP
                                                                    ↳ Rewriting
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(zeros)) → ACTIVE(length(active(zeros)))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(x1)) → MARK(x1)
MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
MARK(length(length(x0))) → ACTIVE(length(active(length(mark(x0)))))
MARK(length(x0)) → ACTIVE(length(x0))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
By rewriting [15] the rule MARK(length(zeros)) → ACTIVE(length(active(zeros))) at position [0,0] we obtained the following new rules:

MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
                                                              ↳ QDP
                                                                ↳ DependencyGraphProof
                                                                  ↳ QDP
                                                                    ↳ Rewriting
QDP
                                                                        ↳ ForwardInstantiation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
MARK(s(x1)) → MARK(x1)
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
MARK(length(length(x0))) → ACTIVE(length(active(length(mark(x0)))))
MARK(length(x0)) → ACTIVE(length(x0))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
By forward instantiating [14] the rule MARK(s(x1)) → MARK(x1) we obtained the following new rules:

MARK(s(length(length(y_0)))) → MARK(length(length(y_0)))
MARK(s(s(y_0))) → MARK(s(y_0))
MARK(s(length(s(y_0)))) → MARK(length(s(y_0)))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(s(length(y_0))) → MARK(length(y_0))
MARK(s(length(zeros))) → MARK(length(zeros))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
                                                              ↳ QDP
                                                                ↳ DependencyGraphProof
                                                                  ↳ QDP
                                                                    ↳ Rewriting
                                                                      ↳ QDP
                                                                        ↳ ForwardInstantiation
QDP
                                                                            ↳ ForwardInstantiation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
MARK(s(s(y_0))) → MARK(s(y_0))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(length(s(y_0)))) → MARK(length(s(y_0)))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(s(length(length(y_0)))) → MARK(length(length(y_0)))
MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
MARK(s(length(y_0))) → MARK(length(y_0))
MARK(length(length(x0))) → ACTIVE(length(active(length(mark(x0)))))
MARK(s(length(zeros))) → MARK(length(zeros))
MARK(length(x0)) → ACTIVE(length(x0))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
By forward instantiating [14] the rule MARK(length(x0)) → ACTIVE(length(x0)) we obtained the following new rules:

MARK(length(cons(y_0, y_1))) → ACTIVE(length(cons(y_0, y_1)))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
                                                              ↳ QDP
                                                                ↳ DependencyGraphProof
                                                                  ↳ QDP
                                                                    ↳ Rewriting
                                                                      ↳ QDP
                                                                        ↳ ForwardInstantiation
                                                                          ↳ QDP
                                                                            ↳ ForwardInstantiation
QDP
                                                                                ↳ ForwardInstantiation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(s(s(y_0))) → MARK(s(y_0))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
MARK(s(length(s(y_0)))) → MARK(length(s(y_0)))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(length(cons(y_0, y_1))) → ACTIVE(length(cons(y_0, y_1)))
MARK(s(length(length(y_0)))) → MARK(length(length(y_0)))
MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
MARK(s(length(y_0))) → MARK(length(y_0))
MARK(length(length(x0))) → ACTIVE(length(active(length(mark(x0)))))
MARK(s(length(zeros))) → MARK(length(zeros))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
By forward instantiating [14] the rule MARK(s(length(y_0))) → MARK(length(y_0)) we obtained the following new rules:

MARK(s(length(length(y_0)))) → MARK(length(length(y_0)))
MARK(s(length(s(y_0)))) → MARK(length(s(y_0)))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(s(length(zeros))) → MARK(length(zeros))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
                                                              ↳ QDP
                                                                ↳ DependencyGraphProof
                                                                  ↳ QDP
                                                                    ↳ Rewriting
                                                                      ↳ QDP
                                                                        ↳ ForwardInstantiation
                                                                          ↳ QDP
                                                                            ↳ ForwardInstantiation
                                                                              ↳ QDP
                                                                                ↳ ForwardInstantiation
QDP
                                                                                    ↳ RuleRemovalProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
MARK(s(s(y_0))) → MARK(s(y_0))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(length(s(y_0)))) → MARK(length(s(y_0)))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(length(cons(y_0, y_1))) → ACTIVE(length(cons(y_0, y_1)))
MARK(s(length(length(y_0)))) → MARK(length(length(y_0)))
MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
MARK(length(length(x0))) → ACTIVE(length(active(length(mark(x0)))))
MARK(s(length(zeros))) → MARK(length(zeros))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
By using the rule removal processor [15] with the following polynomial ordering [25], at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented.
Strictly oriented dependency pairs:

MARK(length(length(x0))) → ACTIVE(length(active(length(mark(x0)))))


Used ordering: POLO with Polynomial interpretation [25]:

POL(0) = 0   
POL(ACTIVE(x1)) = 1 + x1   
POL(MARK(x1)) = 2·x1   
POL(active(x1)) = x1   
POL(cons(x1, x2)) = 2·x1 + 2·x2   
POL(length(x1)) = 1 + 2·x1   
POL(mark(x1)) = x1   
POL(s(x1)) = x1   
POL(zeros) = 0   



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
                                                              ↳ QDP
                                                                ↳ DependencyGraphProof
                                                                  ↳ QDP
                                                                    ↳ Rewriting
                                                                      ↳ QDP
                                                                        ↳ ForwardInstantiation
                                                                          ↳ QDP
                                                                            ↳ ForwardInstantiation
                                                                              ↳ QDP
                                                                                ↳ ForwardInstantiation
                                                                                  ↳ QDP
                                                                                    ↳ RuleRemovalProof
QDP
                                                                                        ↳ DependencyGraphProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(s(length(length(y_0)))) → MARK(length(length(y_0)))
MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(s(s(y_0))) → MARK(s(y_0))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
MARK(s(length(s(y_0)))) → MARK(length(s(y_0)))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(length(cons(y_0, y_1))) → ACTIVE(length(cons(y_0, y_1)))
MARK(s(length(zeros))) → MARK(length(zeros))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 1 SCC with 1 less node.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
                                                              ↳ QDP
                                                                ↳ DependencyGraphProof
                                                                  ↳ QDP
                                                                    ↳ Rewriting
                                                                      ↳ QDP
                                                                        ↳ ForwardInstantiation
                                                                          ↳ QDP
                                                                            ↳ ForwardInstantiation
                                                                              ↳ QDP
                                                                                ↳ ForwardInstantiation
                                                                                  ↳ QDP
                                                                                    ↳ RuleRemovalProof
                                                                                      ↳ QDP
                                                                                        ↳ DependencyGraphProof
QDP
                                                                                            ↳ QDPOrderProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(s(s(y_0))) → MARK(s(y_0))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
MARK(s(length(s(y_0)))) → MARK(length(s(y_0)))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(length(cons(y_0, y_1))) → ACTIVE(length(cons(y_0, y_1)))
MARK(s(length(zeros))) → MARK(length(zeros))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We use the reduction pair processor [15].


The following pairs can be oriented strictly and are deleted.


MARK(length(s(x0))) → ACTIVE(length(active(s(mark(x0)))))
The remaining pairs can at least be oriented weakly.

MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(s(s(y_0))) → MARK(s(y_0))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
MARK(s(length(s(y_0)))) → MARK(length(s(y_0)))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(length(cons(y_0, y_1))) → ACTIVE(length(cons(y_0, y_1)))
MARK(s(length(zeros))) → MARK(length(zeros))
Used ordering: Polynomial interpretation with max and min functions [25]:

POL(0) = 0   
POL(ACTIVE(x1)) = x1   
POL(MARK(x1)) = 1   
POL(active(x1)) = x1   
POL(cons(x1, x2)) = 1   
POL(length(x1)) = x1   
POL(mark(x1)) = x1   
POL(s(x1)) = 0   
POL(zeros) = 1   

The following usable rules [17] were oriented:

mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
mark(s(x1)) → active(s(mark(x1)))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
                                                              ↳ QDP
                                                                ↳ DependencyGraphProof
                                                                  ↳ QDP
                                                                    ↳ Rewriting
                                                                      ↳ QDP
                                                                        ↳ ForwardInstantiation
                                                                          ↳ QDP
                                                                            ↳ ForwardInstantiation
                                                                              ↳ QDP
                                                                                ↳ ForwardInstantiation
                                                                                  ↳ QDP
                                                                                    ↳ RuleRemovalProof
                                                                                      ↳ QDP
                                                                                        ↳ DependencyGraphProof
                                                                                          ↳ QDP
                                                                                            ↳ QDPOrderProof
QDP
                                                                                                ↳ DependencyGraphProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
MARK(s(s(y_0))) → MARK(s(y_0))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(length(s(y_0)))) → MARK(length(s(y_0)))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(length(cons(y_0, y_1))) → ACTIVE(length(cons(y_0, y_1)))
MARK(s(length(zeros))) → MARK(length(zeros))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 1 SCC with 1 less node.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
                                                              ↳ QDP
                                                                ↳ DependencyGraphProof
                                                                  ↳ QDP
                                                                    ↳ Rewriting
                                                                      ↳ QDP
                                                                        ↳ ForwardInstantiation
                                                                          ↳ QDP
                                                                            ↳ ForwardInstantiation
                                                                              ↳ QDP
                                                                                ↳ ForwardInstantiation
                                                                                  ↳ QDP
                                                                                    ↳ RuleRemovalProof
                                                                                      ↳ QDP
                                                                                        ↳ DependencyGraphProof
                                                                                          ↳ QDP
                                                                                            ↳ QDPOrderProof
                                                                                              ↳ QDP
                                                                                                ↳ DependencyGraphProof
QDP
                                                                                                    ↳ QDPOrderProof
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(s(s(y_0))) → MARK(s(y_0))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(length(cons(y_0, y_1))) → ACTIVE(length(cons(y_0, y_1)))
MARK(s(length(zeros))) → MARK(length(zeros))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We use the reduction pair processor [15].


The following pairs can be oriented strictly and are deleted.


MARK(s(s(y_0))) → MARK(s(y_0))
The remaining pairs can at least be oriented weakly.

MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(length(cons(y_0, y_1))) → ACTIVE(length(cons(y_0, y_1)))
MARK(s(length(zeros))) → MARK(length(zeros))
Used ordering: Matrix interpretation [3]:
Non-tuple symbols:
M( active(x1) ) =
/0\
\0/
+
/00\
\01/
·x1

M( cons(x1, x2) ) =
/0\
\0/
+
/00\
\00/
·x1+
/00\
\00/
·x2

M( zeros ) =
/0\
\0/

M( mark(x1) ) =
/0\
\0/
+
/00\
\01/
·x1

M( s(x1) ) =
/0\
\1/
+
/01\
\01/
·x1

M( length(x1) ) =
/0\
\0/
+
/00\
\00/
·x1

M( 0 ) =
/0\
\0/

Tuple symbols:
M( MARK(x1) ) = 0+
[1,0]
·x1

M( ACTIVE(x1) ) = 0+
[0,0]
·x1


Matrix type:
We used a basic matrix type which is not further parametrizeable.


As matrix orders are CE-compatible, we used usable rules w.r.t. argument filtering in the order.
The following usable rules [17] were oriented:

length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
s(active(x1)) → s(x1)
s(mark(x1)) → s(x1)



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
                                  ↳ QDP
                                    ↳ RuleRemovalProof
                                      ↳ QDP
                                        ↳ QDPOrderProof
                                          ↳ QDP
                                            ↳ DependencyGraphProof
                                              ↳ QDP
                                                ↳ QDPOrderProof
                                                  ↳ QDP
                                                    ↳ QDPOrderProof
                                                      ↳ QDP
                                                        ↳ Narrowing
                                                          ↳ QDP
                                                            ↳ Rewriting
                                                              ↳ QDP
                                                                ↳ DependencyGraphProof
                                                                  ↳ QDP
                                                                    ↳ Rewriting
                                                                      ↳ QDP
                                                                        ↳ ForwardInstantiation
                                                                          ↳ QDP
                                                                            ↳ ForwardInstantiation
                                                                              ↳ QDP
                                                                                ↳ ForwardInstantiation
                                                                                  ↳ QDP
                                                                                    ↳ RuleRemovalProof
                                                                                      ↳ QDP
                                                                                        ↳ DependencyGraphProof
                                                                                          ↳ QDP
                                                                                            ↳ QDPOrderProof
                                                                                              ↳ QDP
                                                                                                ↳ DependencyGraphProof
                                                                                                  ↳ QDP
                                                                                                    ↳ QDPOrderProof
QDP
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

MARK(length(zeros)) → ACTIVE(length(mark(cons(0, zeros))))
MARK(length(cons(x0, x1))) → ACTIVE(length(active(cons(mark(x0), x1))))
ACTIVE(length(cons(N, L))) → MARK(s(length(L)))
MARK(s(length(cons(y_0, y_1)))) → MARK(length(cons(y_0, y_1)))
MARK(length(cons(y_0, y_1))) → ACTIVE(length(cons(y_0, y_1)))
MARK(s(length(zeros))) → MARK(length(zeros))

The TRS R consists of the following rules:

mark(s(x1)) → active(s(mark(x1)))
mark(length(x1)) → active(length(mark(x1)))
active(zeros) → mark(cons(0, zeros))
active(length(cons(N, L))) → mark(s(length(L)))
mark(zeros) → active(zeros)
mark(cons(x1, x2)) → active(cons(mark(x1), x2))
mark(0) → active(0)
length(active(x1)) → length(x1)
length(mark(x1)) → length(x1)
cons(mark(x1), x2) → cons(x1, x2)
cons(active(x1), x2) → cons(x1, x2)
s(mark(x1)) → s(x1)
s(active(x1)) → s(x1)

The set Q consists of the following terms:

active(zeros)
active(and(tt, x0))
active(length(nil))
active(length(cons(x0, x1)))
mark(zeros)
mark(cons(x0, x1))
cons(active(x0), x1)
cons(mark(x0), x1)
mark(0)
mark(and(x0, x1))
mark(tt)
mark(length(x0))
length(active(x0))
length(mark(x0))
mark(nil)
mark(s(x0))
s(active(x0))
s(mark(x0))

We have to consider all minimal (P,Q,R)-chains.
We applied the Trivial transformation to transform the context-sensitive TRS to a usual TRS.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
QTRS
          ↳ RRRPoloQTRSProof
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zeros)
and(tt, X) → X
length(nil) → 0
length(cons(N, L)) → s(length(L))

Q is empty.

The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zeros)
and(tt, X) → X
length(nil) → 0
length(cons(N, L)) → s(length(L))

Q is empty.
The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

and(tt, X) → X
length(nil) → 0
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(and(x1, x2)) = 1 + 2·x1 + x2   
POL(cons(x1, x2)) = 2·x1 + 2·x2   
POL(length(x1)) = 1 + x1   
POL(nil) = 1   
POL(s(x1)) = x1   
POL(tt) = 2   
POL(zeros) = 0   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
QTRS
              ↳ Overlay + Local Confluence
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zeros)
length(cons(N, L)) → s(length(L))

Q is empty.

The TRS is overlay and locally confluent. By [19] we can switch to innermost.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ Overlay + Local Confluence
QTRS
                  ↳ DependencyPairsProof
      ↳ Improved Ferreira Ribeiro-Transformation

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zeros)
length(cons(N, L)) → s(length(L))

The set Q consists of the following terms:

zeros
length(cons(x0, x1))


Using Dependency Pairs [1,15] we result in the following initial DP problem:
Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(L)
ZEROSZEROS

The TRS R consists of the following rules:

zeroscons(0, zeros)
length(cons(N, L)) → s(length(L))

The set Q consists of the following terms:

zeros
length(cons(x0, x1))

We have to consider all minimal (P,Q,R)-chains.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ Overlay + Local Confluence
                ↳ QTRS
                  ↳ DependencyPairsProof
QDP
                      ↳ DependencyGraphProof
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(L)
ZEROSZEROS

The TRS R consists of the following rules:

zeroscons(0, zeros)
length(cons(N, L)) → s(length(L))

The set Q consists of the following terms:

zeros
length(cons(x0, x1))

We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 2 SCCs.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ Overlay + Local Confluence
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
QDP
                            ↳ UsableRulesProof
                          ↳ QDP
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(L)

The TRS R consists of the following rules:

zeroscons(0, zeros)
length(cons(N, L)) → s(length(L))

The set Q consists of the following terms:

zeros
length(cons(x0, x1))

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ Overlay + Local Confluence
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                            ↳ UsableRulesProof
QDP
                                ↳ QReductionProof
                          ↳ QDP
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(L)

R is empty.
The set Q consists of the following terms:

zeros
length(cons(x0, x1))

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

zeros
length(cons(x0, x1))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ Overlay + Local Confluence
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
QDP
                                    ↳ QDPSizeChangeProof
                          ↳ QDP
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(L)

R is empty.
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
By using the subterm criterion [20] together with the size-change analysis [32] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ Overlay + Local Confluence
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
QDP
                            ↳ UsableRulesProof
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

ZEROSZEROS

The TRS R consists of the following rules:

zeroscons(0, zeros)
length(cons(N, L)) → s(length(L))

The set Q consists of the following terms:

zeros
length(cons(x0, x1))

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ Overlay + Local Confluence
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
QDP
                                ↳ QReductionProof
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

ZEROSZEROS

R is empty.
The set Q consists of the following terms:

zeros
length(cons(x0, x1))

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

zeros
length(cons(x0, x1))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ Overlay + Local Confluence
                ↳ QTRS
                  ↳ DependencyPairsProof
                    ↳ QDP
                      ↳ DependencyGraphProof
                        ↳ AND
                          ↳ QDP
                          ↳ QDP
                            ↳ UsableRulesProof
                              ↳ QDP
                                ↳ QReductionProof
QDP
                                    ↳ NonTerminationProof
      ↳ Improved Ferreira Ribeiro-Transformation

Q DP problem:
The TRS P consists of the following rules:

ZEROSZEROS

R is empty.
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
We used the non-termination processor [17] to show that the DP problem is infinite.
Found a loop by semiunifying a rule from P directly.

The TRS P consists of the following rules:

ZEROSZEROS

The TRS R consists of the following rules:none


s = ZEROS evaluates to t =ZEROS

Thus s starts an infinite chain as s semiunifies with t with the following substitutions:




Rewriting sequence

The DP semiunifies directly so there is only one rewrite step from ZEROS to ZEROS.




We applied the Improved Ferreira Ribeiro transformation [5,11] to transform the context-sensitive TRS to a usual TRS.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
QTRS
          ↳ RRRPoloQTRSProof

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
and(tt, X) → a(X)
length(nil) → 0
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.

The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
and(tt, X) → a(X)
length(nil) → 0
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.
The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

and(tt, X) → a(X)
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(a(x1)) = x1   
POL(and(x1, x2)) = x1 + 2·x2   
POL(cons(x1, x2)) = 2·x1 + 2·x2   
POL(length(x1)) = 2·x1   
POL(nil) = 0   
POL(s(x1)) = 2·x1   
POL(tt) = 1   
POL(zeros) = 0   
POL(zerosInact) = 0   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
QTRS
              ↳ RRRPoloQTRSProof

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(nil) → 0
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.

The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(nil) → 0
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.
The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

length(nil) → 0
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(a(x1)) = x1   
POL(cons(x1, x2)) = 2·x1 + 2·x2   
POL(length(x1)) = 2·x1   
POL(nil) = 2   
POL(s(x1)) = 2·x1   
POL(zeros) = 0   
POL(zerosInact) = 0   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
QTRS
                  ↳ RRRPoloQTRSProof

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.

The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(x) → x
zeroszerosInact
a(zerosInact) → zeros

Q is empty.
The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

zeroszerosInact
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(a(x1)) = 2·x1   
POL(cons(x1, x2)) = x1 + 2·x2   
POL(length(x1)) = 2·x1   
POL(s(x1)) = x1   
POL(zeros) = 2   
POL(zerosInact) = 1   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
QTRS
                      ↳ RRRPoloQTRSProof

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(x) → x
a(zerosInact) → zeros

Q is empty.

The following Q TRS is given: Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(x) → x
a(zerosInact) → zeros

Q is empty.
The following rules can be removed by the rule removal processor [15] because they are oriented strictly by a polynomial ordering:

a(x) → x
Used ordering:
Polynomial interpretation [25]:

POL(0) = 0   
POL(a(x1)) = 1 + x1   
POL(cons(x1, x2)) = 1 + 2·x1 + x2   
POL(length(x1)) = x1   
POL(s(x1)) = x1   
POL(zeros) = 1   
POL(zerosInact) = 0   




↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
QTRS
                          ↳ Overlay + Local Confluence

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(zerosInact) → zeros

Q is empty.

The TRS is overlay and locally confluent. By [19] we can switch to innermost.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
QTRS
                              ↳ DependencyPairsProof

Q restricted rewrite system:
The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(zerosInact) → zeros

The set Q consists of the following terms:

zeros
length(cons(x0, x1))
a(zerosInact)


Using Dependency Pairs [1,15] we result in the following initial DP problem:
Q DP problem:
The TRS P consists of the following rules:

A(zerosInact) → ZEROS
LENGTH(cons(N, L)) → A(L)
LENGTH(cons(N, L)) → LENGTH(a(L))

The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(zerosInact) → zeros

The set Q consists of the following terms:

zeros
length(cons(x0, x1))
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
QDP
                                  ↳ DependencyGraphProof

Q DP problem:
The TRS P consists of the following rules:

A(zerosInact) → ZEROS
LENGTH(cons(N, L)) → A(L)
LENGTH(cons(N, L)) → LENGTH(a(L))

The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(zerosInact) → zeros

The set Q consists of the following terms:

zeros
length(cons(x0, x1))
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 1 SCC with 2 less nodes.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
QDP
                                      ↳ UsableRulesProof

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(a(L))

The TRS R consists of the following rules:

zeroscons(0, zerosInact)
length(cons(N, L)) → s(length(a(L)))
a(zerosInact) → zeros

The set Q consists of the following terms:

zeros
length(cons(x0, x1))
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
QDP
                                          ↳ QReductionProof

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(a(L))

The TRS R consists of the following rules:

a(zerosInact) → zeros
zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros
length(cons(x0, x1))
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

length(cons(x0, x1))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
QDP
                                              ↳ Narrowing

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(N, L)) → LENGTH(a(L))

The TRS R consists of the following rules:

a(zerosInact) → zeros
zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
By narrowing [15] the rule LENGTH(cons(N, L)) → LENGTH(a(L)) at position [0] we obtained the following new rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(zeros)



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
QDP
                                                  ↳ UsableRulesProof

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(zeros)

The TRS R consists of the following rules:

a(zerosInact) → zeros
zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
QDP
                                                      ↳ QReductionProof

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(zeros)

The TRS R consists of the following rules:

zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros
a(zerosInact)

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

a(zerosInact)



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
                                                    ↳ QDP
                                                      ↳ QReductionProof
QDP
                                                          ↳ Rewriting

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(zeros)

The TRS R consists of the following rules:

zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros

We have to consider all minimal (P,Q,R)-chains.
By rewriting [15] the rule LENGTH(cons(y0, zerosInact)) → LENGTH(zeros) at position [0] we obtained the following new rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(cons(0, zerosInact))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
                                                    ↳ QDP
                                                      ↳ QReductionProof
                                                        ↳ QDP
                                                          ↳ Rewriting
QDP
                                                              ↳ UsableRulesProof

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(cons(0, zerosInact))

The TRS R consists of the following rules:

zeroscons(0, zerosInact)

The set Q consists of the following terms:

zeros

We have to consider all minimal (P,Q,R)-chains.
As all Q-normal forms are R-normal forms we are in the innermost case. Hence, by the usable rules processor [15] we can delete all non-usable rules [17] from R.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
                                                    ↳ QDP
                                                      ↳ QReductionProof
                                                        ↳ QDP
                                                          ↳ Rewriting
                                                            ↳ QDP
                                                              ↳ UsableRulesProof
QDP
                                                                  ↳ QReductionProof

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(cons(0, zerosInact))

R is empty.
The set Q consists of the following terms:

zeros

We have to consider all minimal (P,Q,R)-chains.
We deleted the following terms from Q as each root-symbol of these terms does neither occur in P nor in R.

zeros



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
                                                    ↳ QDP
                                                      ↳ QReductionProof
                                                        ↳ QDP
                                                          ↳ Rewriting
                                                            ↳ QDP
                                                              ↳ UsableRulesProof
                                                                ↳ QDP
                                                                  ↳ QReductionProof
QDP
                                                                      ↳ Instantiation

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(y0, zerosInact)) → LENGTH(cons(0, zerosInact))

R is empty.
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
By instantiating [15] the rule LENGTH(cons(y0, zerosInact)) → LENGTH(cons(0, zerosInact)) we obtained the following new rules:

LENGTH(cons(0, zerosInact)) → LENGTH(cons(0, zerosInact))



↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
      ↳ Zantema-Transformation
      ↳ Innermost Giesl Middeldorp-Transformation
      ↳ Trivial-Transformation
      ↳ Improved Ferreira Ribeiro-Transformation
        ↳ QTRS
          ↳ RRRPoloQTRSProof
            ↳ QTRS
              ↳ RRRPoloQTRSProof
                ↳ QTRS
                  ↳ RRRPoloQTRSProof
                    ↳ QTRS
                      ↳ RRRPoloQTRSProof
                        ↳ QTRS
                          ↳ Overlay + Local Confluence
                            ↳ QTRS
                              ↳ DependencyPairsProof
                                ↳ QDP
                                  ↳ DependencyGraphProof
                                    ↳ QDP
                                      ↳ UsableRulesProof
                                        ↳ QDP
                                          ↳ QReductionProof
                                            ↳ QDP
                                              ↳ Narrowing
                                                ↳ QDP
                                                  ↳ UsableRulesProof
                                                    ↳ QDP
                                                      ↳ QReductionProof
                                                        ↳ QDP
                                                          ↳ Rewriting
                                                            ↳ QDP
                                                              ↳ UsableRulesProof
                                                                ↳ QDP
                                                                  ↳ QReductionProof
                                                                    ↳ QDP
                                                                      ↳ Instantiation
QDP
                                                                          ↳ NonTerminationProof

Q DP problem:
The TRS P consists of the following rules:

LENGTH(cons(0, zerosInact)) → LENGTH(cons(0, zerosInact))

R is empty.
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
We used the non-termination processor [17] to show that the DP problem is infinite.
Found a loop by semiunifying a rule from P directly.

The TRS P consists of the following rules:

LENGTH(cons(0, zerosInact)) → LENGTH(cons(0, zerosInact))

The TRS R consists of the following rules:none


s = LENGTH(cons(0, zerosInact)) evaluates to t =LENGTH(cons(0, zerosInact))

Thus s starts an infinite chain as s semiunifies with t with the following substitutions:




Rewriting sequence

The DP semiunifies directly so there is only one rewrite step from LENGTH(cons(0, zerosInact)) to LENGTH(cons(0, zerosInact)).