Termination of the following Term Rewriting System could be proven:

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

from(X) → cons(X, from(s(X)))
after(0, XS) → XS
after(s(N), cons(X, XS)) → after(N, XS)

The replacement map contains the following entries:

from: {1}
cons: {1}
s: {1}
after: {1, 2}
0: empty set


CSR
  ↳ CSRInnermostProof

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

from(X) → cons(X, from(s(X)))
after(0, XS) → XS
after(s(N), cons(X, XS)) → after(N, XS)

The replacement map contains the following entries:

from: {1}
cons: {1}
s: {1}
after: {1, 2}
0: empty set

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

↳ CSR
  ↳ CSRInnermostProof
CSR
      ↳ CSDependencyPairsProof

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

from(X) → cons(X, from(s(X)))
after(0, XS) → XS
after(s(N), cons(X, XS)) → after(N, XS)

The replacement map contains the following entries:

from: {1}
cons: {1}
s: {1}
after: {1, 2}
0: empty set

Innermost Strategy.

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

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
QCSDP
          ↳ QCSDependencyGraphProof

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

The ordinary context-sensitive dependency pairs DPo are:

AFTER(s(N), cons(X, XS)) → AFTER(N, XS)

The collapsing dependency pairs are DPc:

AFTER(s(N), cons(X, XS)) → XS


The hidden terms of R are:

from(s(X))

Every hiding context is built from:

s on positions {1}
from on positions {1}

Hence, the new unhiding pairs DPu are :

AFTER(s(N), cons(X, XS)) → U(XS)
U(s(x_0)) → U(x_0)
U(from(x_0)) → U(x_0)
U(from(s(X))) → FROM(s(X))

The TRS R consists of the following rules:

from(X) → cons(X, from(s(X)))
after(0, XS) → XS
after(s(N), cons(X, XS)) → after(N, XS)

The set Q consists of the following terms:

from(x0)
after(0, x0)
after(s(x0), cons(x1, x2))


The approximation of the Context-Sensitive Dependency Graph contains 2 SCCs with 2 less nodes.


↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
        ↳ QCSDP
          ↳ QCSDependencyGraphProof
            ↳ AND
QCSDP
                ↳ QCSDPSubtermProof
              ↳ QCSDP

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

The TRS P consists of the following rules:

U(s(x_0)) → U(x_0)
U(from(x_0)) → U(x_0)

The TRS R consists of the following rules:

from(X) → cons(X, from(s(X)))
after(0, XS) → XS
after(s(N), cons(X, XS)) → after(N, XS)

The set Q consists of the following terms:

from(x0)
after(0, x0)
after(s(x0), cons(x1, x2))


We use the subterm processor [20].


The following pairs can be oriented strictly and are deleted.


U(s(x_0)) → U(x_0)
U(from(x_0)) → U(x_0)
The remaining pairs can at least be oriented weakly.
none
Used ordering: Combined order from the following AFS and order.
U(x1)  =  x1

Subterm Order


↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
        ↳ QCSDP
          ↳ QCSDependencyGraphProof
            ↳ AND
              ↳ QCSDP
                ↳ QCSDPSubtermProof
QCSDP
                    ↳ PIsEmptyProof
              ↳ QCSDP

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

The TRS P consists of the following rules:
none

The TRS R consists of the following rules:

from(X) → cons(X, from(s(X)))
after(0, XS) → XS
after(s(N), cons(X, XS)) → after(N, XS)

The set Q consists of the following terms:

from(x0)
after(0, x0)
after(s(x0), cons(x1, x2))


The TRS P is empty. Hence, there is no (P,Q,R,µ)-chain.

↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
        ↳ QCSDP
          ↳ QCSDependencyGraphProof
            ↳ AND
              ↳ QCSDP
QCSDP
                ↳ QCSDPSubtermProof

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

The TRS P consists of the following rules:

AFTER(s(N), cons(X, XS)) → AFTER(N, XS)

The TRS R consists of the following rules:

from(X) → cons(X, from(s(X)))
after(0, XS) → XS
after(s(N), cons(X, XS)) → after(N, XS)

The set Q consists of the following terms:

from(x0)
after(0, x0)
after(s(x0), cons(x1, x2))


We use the subterm processor [20].


The following pairs can be oriented strictly and are deleted.


AFTER(s(N), cons(X, XS)) → AFTER(N, XS)
The remaining pairs can at least be oriented weakly.
none
Used ordering: Combined order from the following AFS and order.
AFTER(x1, x2)  =  x1

Subterm Order


↳ CSR
  ↳ CSRInnermostProof
    ↳ CSR
      ↳ CSDependencyPairsProof
        ↳ QCSDP
          ↳ QCSDependencyGraphProof
            ↳ AND
              ↳ QCSDP
              ↳ QCSDP
                ↳ QCSDPSubtermProof
QCSDP
                    ↳ PIsEmptyProof

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

The TRS P consists of the following rules:
none

The TRS R consists of the following rules:

from(X) → cons(X, from(s(X)))
after(0, XS) → XS
after(s(N), cons(X, XS)) → after(N, XS)

The set Q consists of the following terms:

from(x0)
after(0, x0)
after(s(x0), cons(x1, x2))


The TRS P is empty. Hence, there is no (P,Q,R,µ)-chain.