Termination w.r.t. Q of the following Term Rewriting System could be proven:
Q restricted rewrite system:
The TRS R consists of the following rules:
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
tower(x, y) → towerIter(x, y, s(0))
towerIter(0, y, z) → z
towerIter(s(x), y, z) → towerIter(p(s(x)), y, exp(y, z))
Q is empty.
↳ QTRS
  ↳ Overlay + Local Confluence
Q restricted rewrite system:
The TRS R consists of the following rules:
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
tower(x, y) → towerIter(x, y, s(0))
towerIter(0, y, z) → z
towerIter(s(x), y, z) → towerIter(p(s(x)), y, exp(y, z))
Q is empty.
The TRS is overlay and locally confluent. By [19] we can switch to innermost.
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
Q restricted rewrite system:
The TRS R consists of the following rules:
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
tower(x, y) → towerIter(x, y, s(0))
towerIter(0, y, z) → z
towerIter(s(x), y, z) → towerIter(p(s(x)), y, exp(y, z))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
Using Dependency Pairs [1,15] we result in the following initial DP problem:
Q DP problem:
The TRS P consists of the following rules:
TOWERITER(s(x), y, z) → TOWERITER(p(s(x)), y, exp(y, z))
TIMES(s(x), y) → P(s(x))
TIMES(s(x), y) → PLUS(y, times(p(s(x)), y))
TOWERITER(s(x), y, z) → EXP(y, z)
P(s(s(x))) → P(s(x))
EXP(x, s(y)) → EXP(x, y)
TOWERITER(s(x), y, z) → P(s(x))
EXP(x, s(y)) → TIMES(x, exp(x, y))
PLUS(s(x), y) → PLUS(p(s(x)), y)
PLUS(s(x), y) → P(s(x))
TOWER(x, y) → TOWERITER(x, y, s(0))
TIMES(s(x), y) → TIMES(p(s(x)), y)
The TRS R consists of the following rules:
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
tower(x, y) → towerIter(x, y, s(0))
towerIter(0, y, z) → z
towerIter(s(x), y, z) → towerIter(p(s(x)), y, exp(y, z))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
We have to consider all minimal (P,Q,R)-chains.
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
Q DP problem:
The TRS P consists of the following rules:
TOWERITER(s(x), y, z) → TOWERITER(p(s(x)), y, exp(y, z))
TIMES(s(x), y) → P(s(x))
TIMES(s(x), y) → PLUS(y, times(p(s(x)), y))
TOWERITER(s(x), y, z) → EXP(y, z)
P(s(s(x))) → P(s(x))
EXP(x, s(y)) → EXP(x, y)
TOWERITER(s(x), y, z) → P(s(x))
EXP(x, s(y)) → TIMES(x, exp(x, y))
PLUS(s(x), y) → PLUS(p(s(x)), y)
PLUS(s(x), y) → P(s(x))
TOWER(x, y) → TOWERITER(x, y, s(0))
TIMES(s(x), y) → TIMES(p(s(x)), y)
The TRS R consists of the following rules:
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
tower(x, y) → towerIter(x, y, s(0))
towerIter(0, y, z) → z
towerIter(s(x), y, z) → towerIter(p(s(x)), y, exp(y, z))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
                ↳ UsableRulesProof
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
P(s(s(x))) → P(s(x))
The TRS R consists of the following rules:
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
tower(x, y) → towerIter(x, y, s(0))
towerIter(0, y, z) → z
towerIter(s(x), y, z) → towerIter(p(s(x)), y, exp(y, z))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
P(s(s(x))) → P(s(x))
R is empty.
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
                      ↳ QDP
                        ↳ QDPSizeChangeProof
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
P(s(s(x))) → P(s(x))
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:
- P(s(s(x))) → P(s(x))
 The graph contains the following edges 1 > 1
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
              ↳ QDP
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
PLUS(s(x), y) → PLUS(p(s(x)), y)
The TRS R consists of the following rules:
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
tower(x, y) → towerIter(x, y, s(0))
towerIter(0, y, z) → z
towerIter(s(x), y, z) → towerIter(p(s(x)), y, exp(y, z))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
              ↳ QDP
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
PLUS(s(x), y) → PLUS(p(s(x)), y)
The TRS R consists of the following rules:
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
                      ↳ QDP
                        ↳ RuleRemovalProof
              ↳ QDP
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
PLUS(s(x), y) → PLUS(p(s(x)), y)
The TRS R consists of the following rules:
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
The set Q consists of the following terms:
p(s(0))
p(s(s(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 rules of the TRS R:
p(s(0)) → 0
Used ordering: POLO with Polynomial interpretation [25]:
POL(0) = 1   
POL(PLUS(x1, x2)) = x1 + x2   
POL(p(x1)) = x1   
POL(s(x1)) = 2·x1   
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
                      ↳ QDP
                        ↳ RuleRemovalProof
                          ↳ QDP
                            ↳ QDPOrderProof
              ↳ QDP
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
PLUS(s(x), y) → PLUS(p(s(x)), y)
The TRS R consists of the following rules:
p(s(s(x))) → s(p(s(x)))
The set Q consists of the following terms:
p(s(0))
p(s(s(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.
PLUS(s(x), y) → PLUS(p(s(x)), y)
The remaining pairs can at least be oriented weakly.
none
Used ordering:  Matrix interpretation [3]:
Non-tuple symbols: 
Tuple symbols: 
| M( PLUS(x1, x2) ) = | 0 | + |  | · | x1 | + |  | · | x2 | 
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:
p(s(s(x))) → s(p(s(x)))
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
                      ↳ QDP
                        ↳ RuleRemovalProof
                          ↳ QDP
                            ↳ QDPOrderProof
                              ↳ QDP
                                ↳ PisEmptyProof
              ↳ QDP
              ↳ QDP
              ↳ QDP
Q DP problem:
P is empty.
The TRS R consists of the following rules:
p(s(s(x))) → s(p(s(x)))
The set Q consists of the following terms:
p(s(0))
p(s(s(x0)))
We have to consider all minimal (P,Q,R)-chains.
The TRS P is empty. Hence, there is no (P,Q,R) chain.
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
TIMES(s(x), y) → TIMES(p(s(x)), y)
The TRS R consists of the following rules:
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
tower(x, y) → towerIter(x, y, s(0))
towerIter(0, y, z) → z
towerIter(s(x), y, z) → towerIter(p(s(x)), y, exp(y, z))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
TIMES(s(x), y) → TIMES(p(s(x)), y)
The TRS R consists of the following rules:
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
                      ↳ QDP
                        ↳ RuleRemovalProof
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
TIMES(s(x), y) → TIMES(p(s(x)), y)
The TRS R consists of the following rules:
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
The set Q consists of the following terms:
p(s(0))
p(s(s(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 rules of the TRS R:
p(s(0)) → 0
Used ordering: POLO with Polynomial interpretation [25]:
POL(0) = 1   
POL(TIMES(x1, x2)) = x1 + x2   
POL(p(x1)) = x1   
POL(s(x1)) = 2·x1   
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
                      ↳ QDP
                        ↳ RuleRemovalProof
                          ↳ QDP
                            ↳ QDPOrderProof
              ↳ QDP
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
TIMES(s(x), y) → TIMES(p(s(x)), y)
The TRS R consists of the following rules:
p(s(s(x))) → s(p(s(x)))
The set Q consists of the following terms:
p(s(0))
p(s(s(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.
TIMES(s(x), y) → TIMES(p(s(x)), y)
The remaining pairs can at least be oriented weakly.
none
Used ordering:  Matrix interpretation [3]:
Non-tuple symbols: 
Tuple symbols: 
| M( TIMES(x1, x2) ) = | 0 | + |  | · | x1 | + |  | · | x2 | 
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:
p(s(s(x))) → s(p(s(x)))
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
                      ↳ QDP
                        ↳ RuleRemovalProof
                          ↳ QDP
                            ↳ QDPOrderProof
                              ↳ QDP
                                ↳ PisEmptyProof
              ↳ QDP
              ↳ QDP
Q DP problem:
P is empty.
The TRS R consists of the following rules:
p(s(s(x))) → s(p(s(x)))
The set Q consists of the following terms:
p(s(0))
p(s(s(x0)))
We have to consider all minimal (P,Q,R)-chains.
The TRS P is empty. Hence, there is no (P,Q,R) chain.
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
EXP(x, s(y)) → EXP(x, y)
The TRS R consists of the following rules:
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
tower(x, y) → towerIter(x, y, s(0))
towerIter(0, y, z) → z
towerIter(s(x), y, z) → towerIter(p(s(x)), y, exp(y, z))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
EXP(x, s(y)) → EXP(x, y)
R is empty.
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
                      ↳ QDP
                        ↳ QDPSizeChangeProof
              ↳ QDP
Q DP problem:
The TRS P consists of the following rules:
EXP(x, s(y)) → EXP(x, y)
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:
- EXP(x, s(y)) → EXP(x, y)
 The graph contains the following edges 1 >= 1, 2 > 2
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
Q DP problem:
The TRS P consists of the following rules:
TOWERITER(s(x), y, z) → TOWERITER(p(s(x)), y, exp(y, z))
The TRS R consists of the following rules:
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
tower(x, y) → towerIter(x, y, s(0))
towerIter(0, y, z) → z
towerIter(s(x), y, z) → towerIter(p(s(x)), y, exp(y, z))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
Q DP problem:
The TRS P consists of the following rules:
TOWERITER(s(x), y, z) → TOWERITER(p(s(x)), y, exp(y, z))
The TRS R consists of the following rules:
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
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.
tower(x0, x1)
towerIter(0, x0, x1)
towerIter(s(x0), x1, x2)
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
                      ↳ QDP
                        ↳ QDPOrderProof
Q DP problem:
The TRS P consists of the following rules:
TOWERITER(s(x), y, z) → TOWERITER(p(s(x)), y, exp(y, z))
The TRS R consists of the following rules:
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(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.
TOWERITER(s(x), y, z) → TOWERITER(p(s(x)), y, exp(y, z))
The remaining pairs can at least be oriented weakly.
none
Used ordering:  Matrix interpretation [3]:
Non-tuple symbols: 
| M( plus(x1, x2) ) = |  | + |  | · | x1 | + |  | · | x2 | 
| M( exp(x1, x2) ) = |  | + |  | · | x1 | + |  | · | x2 | 
| M( times(x1, x2) ) = |  | + |  | · | x1 | + |  | · | x2 | 
Tuple symbols: 
| M( TOWERITER(x1, ..., x3) ) = | 0 | + |  | · | x1 | + |  | · | x2 | + |  | · | x3 | 
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:
p(s(s(x))) → s(p(s(x)))
p(s(0)) → 0
↳ QTRS
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ DependencyGraphProof
            ↳ AND
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
              ↳ QDP
                ↳ UsableRulesProof
                  ↳ QDP
                    ↳ QReductionProof
                      ↳ QDP
                        ↳ QDPOrderProof
                          ↳ QDP
                            ↳ PisEmptyProof
Q DP problem:
P is empty.
The TRS R consists of the following rules:
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))
exp(x, 0) → s(0)
exp(x, s(y)) → times(x, exp(x, y))
times(0, y) → 0
times(s(x), y) → plus(y, times(p(s(x)), y))
plus(0, x) → x
plus(s(x), y) → s(plus(p(s(x)), y))
The set Q consists of the following terms:
plus(0, x0)
plus(s(x0), x1)
times(0, x0)
times(s(x0), x1)
exp(x0, 0)
exp(x0, s(x1))
p(s(0))
p(s(s(x0)))
We have to consider all minimal (P,Q,R)-chains.
The TRS P is empty. Hence, there is no (P,Q,R) chain.