NO Termination w.r.t. Q proof of ../tpdb/TRS/TRCSR/Ex9_Luc06_FR.trs
Termination w.r.t. Q of the following Term Rewriting System could be disproven:

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

f(n__a, X, X) → f(activate(X), b, n__b)
ba
an__a
bn__b
activate(n__a) → a
activate(n__b) → b
activate(X) → X

Q is empty.


QTRS
  ↳ DependencyPairsProof

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

f(n__a, X, X) → f(activate(X), b, n__b)
ba
an__a
bn__b
activate(n__a) → a
activate(n__b) → b
activate(X) → X

Q is empty.

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

BA
F(n__a, X, X) → F(activate(X), b, n__b)
ACTIVATE(n__a) → A
F(n__a, X, X) → B
F(n__a, X, X) → ACTIVATE(X)
ACTIVATE(n__b) → B

The TRS R consists of the following rules:

f(n__a, X, X) → f(activate(X), b, n__b)
ba
an__a
bn__b
activate(n__a) → a
activate(n__b) → b
activate(X) → X

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

↳ QTRS
  ↳ DependencyPairsProof
QDP
      ↳ DependencyGraphProof

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

BA
F(n__a, X, X) → F(activate(X), b, n__b)
ACTIVATE(n__a) → A
F(n__a, X, X) → B
F(n__a, X, X) → ACTIVATE(X)
ACTIVATE(n__b) → B

The TRS R consists of the following rules:

f(n__a, X, X) → f(activate(X), b, n__b)
ba
an__a
bn__b
activate(n__a) → a
activate(n__b) → b
activate(X) → X

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 1 SCC with 5 less nodes.

↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
QDP
          ↳ UsableRulesProof

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

F(n__a, X, X) → F(activate(X), b, n__b)

The TRS R consists of the following rules:

f(n__a, X, X) → f(activate(X), b, n__b)
ba
an__a
bn__b
activate(n__a) → a
activate(n__b) → b
activate(X) → X

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
We can use the usable rules and reduction pair processor [15] with the Ce-compatible extension of the polynomial order that maps every function symbol to the sum of its argument. Then, we can delete all non-usable rules [17] from R.

↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
QDP
              ↳ Instantiation

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

F(n__a, X, X) → F(activate(X), b, n__b)

The TRS R consists of the following rules:

activate(n__a) → a
activate(n__b) → b
activate(X) → X
ba
bn__b
an__a

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
By instantiating [15] the rule F(n__a, X, X) → F(activate(X), b, n__b) we obtained the following new rules:

F(n__a, n__b, n__b) → F(activate(n__b), b, n__b)



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
QDP
                  ↳ UsableRulesProof

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

F(n__a, n__b, n__b) → F(activate(n__b), b, n__b)

The TRS R consists of the following rules:

activate(n__a) → a
activate(n__b) → b
activate(X) → X
ba
bn__b
an__a

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
We can use the usable rules and reduction pair processor [15] with the Ce-compatible extension of the polynomial order that maps every function symbol to the sum of its argument. Then, we can delete all non-usable rules [17] from R.

↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
QDP
                      ↳ Narrowing

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

F(n__a, n__b, n__b) → F(activate(n__b), b, n__b)

The TRS R consists of the following rules:

activate(n__b) → b
activate(X) → X
ba
bn__b
an__a

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
By narrowing [15] the rule F(n__a, n__b, n__b) → F(activate(n__b), b, n__b) at position [0] we obtained the following new rules:

F(n__a, n__b, n__b) → F(n__b, b, n__b)
F(n__a, n__b, n__b) → F(b, b, n__b)



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
QDP
                          ↳ DependencyGraphProof

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

F(n__a, n__b, n__b) → F(n__b, b, n__b)
F(n__a, n__b, n__b) → F(b, b, n__b)

The TRS R consists of the following rules:

activate(n__b) → b
activate(X) → X
ba
bn__b
an__a

Q is empty.
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.

↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
QDP
                              ↳ UsableRulesProof

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

F(n__a, n__b, n__b) → F(b, b, n__b)

The TRS R consists of the following rules:

activate(n__b) → b
activate(X) → X
ba
bn__b
an__a

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
We can use the usable rules and reduction pair processor [15] with the Ce-compatible extension of the polynomial order that maps every function symbol to the sum of its argument. Then, we can delete all non-usable rules [17] from R.

↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
QDP
                                  ↳ Narrowing

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

F(n__a, n__b, n__b) → F(b, b, n__b)

The TRS R consists of the following rules:

ba
bn__b
an__a

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
By narrowing [15] the rule F(n__a, n__b, n__b) → F(b, b, n__b) at position [1] we obtained the following new rules:

F(n__a, n__b, n__b) → F(b, n__b, n__b)
F(n__a, n__b, n__b) → F(b, a, n__b)



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
QDP
                                      ↳ Narrowing

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

F(n__a, n__b, n__b) → F(b, a, n__b)
F(n__a, n__b, n__b) → F(b, n__b, n__b)

The TRS R consists of the following rules:

ba
bn__b
an__a

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
By narrowing [15] the rule F(n__a, n__b, n__b) → F(b, a, n__b) at position [1] we obtained the following new rules:

F(n__a, n__b, n__b) → F(b, n__a, n__b)



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
                                    ↳ QDP
                                      ↳ Narrowing
QDP
                                          ↳ DependencyGraphProof

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

F(n__a, n__b, n__b) → F(b, n__a, n__b)
F(n__a, n__b, n__b) → F(b, n__b, n__b)

The TRS R consists of the following rules:

ba
bn__b
an__a

Q is empty.
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.

↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
                                    ↳ QDP
                                      ↳ Narrowing
                                        ↳ QDP
                                          ↳ DependencyGraphProof
QDP
                                              ↳ RuleRemovalProof

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

F(n__a, n__b, n__b) → F(b, n__b, n__b)

The TRS R consists of the following rules:

ba
bn__b
an__a

Q is empty.
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:

bn__b

Used ordering: POLO with Polynomial interpretation [25]:

POL(F(x1, x2, x3)) = 2·x1 + x2 + x3   
POL(a) = 1   
POL(b) = 1   
POL(n__a) = 1   
POL(n__b) = 0   



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
                                    ↳ QDP
                                      ↳ Narrowing
                                        ↳ QDP
                                          ↳ DependencyGraphProof
                                            ↳ QDP
                                              ↳ RuleRemovalProof
QDP
                                                  ↳ MNOCProof

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

F(n__a, n__b, n__b) → F(b, n__b, n__b)

The TRS R consists of the following rules:

ba
an__a

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
We use the modular non-overlap check [15] to enlarge Q to all left-hand sides of R.

↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
                                    ↳ QDP
                                      ↳ Narrowing
                                        ↳ QDP
                                          ↳ DependencyGraphProof
                                            ↳ QDP
                                              ↳ RuleRemovalProof
                                                ↳ QDP
                                                  ↳ MNOCProof
QDP
                                                      ↳ Rewriting

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

F(n__a, n__b, n__b) → F(b, n__b, n__b)

The TRS R consists of the following rules:

ba
an__a

The set Q consists of the following terms:

b
a

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

F(n__a, n__b, n__b) → F(a, n__b, n__b)



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
                                    ↳ QDP
                                      ↳ Narrowing
                                        ↳ QDP
                                          ↳ DependencyGraphProof
                                            ↳ QDP
                                              ↳ RuleRemovalProof
                                                ↳ QDP
                                                  ↳ MNOCProof
                                                    ↳ QDP
                                                      ↳ Rewriting
QDP
                                                          ↳ UsableRulesProof

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

F(n__a, n__b, n__b) → F(a, n__b, n__b)

The TRS R consists of the following rules:

ba
an__a

The set Q consists of the following terms:

b
a

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
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
                                    ↳ QDP
                                      ↳ Narrowing
                                        ↳ QDP
                                          ↳ DependencyGraphProof
                                            ↳ QDP
                                              ↳ RuleRemovalProof
                                                ↳ QDP
                                                  ↳ MNOCProof
                                                    ↳ QDP
                                                      ↳ Rewriting
                                                        ↳ QDP
                                                          ↳ UsableRulesProof
QDP
                                                              ↳ QReductionProof

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

F(n__a, n__b, n__b) → F(a, n__b, n__b)

The TRS R consists of the following rules:

an__a

The set Q consists of the following terms:

b
a

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.

b



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
                                    ↳ QDP
                                      ↳ Narrowing
                                        ↳ QDP
                                          ↳ DependencyGraphProof
                                            ↳ QDP
                                              ↳ RuleRemovalProof
                                                ↳ QDP
                                                  ↳ MNOCProof
                                                    ↳ QDP
                                                      ↳ Rewriting
                                                        ↳ QDP
                                                          ↳ UsableRulesProof
                                                            ↳ QDP
                                                              ↳ QReductionProof
QDP
                                                                  ↳ Rewriting

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

F(n__a, n__b, n__b) → F(a, n__b, n__b)

The TRS R consists of the following rules:

an__a

The set Q consists of the following terms:

a

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

F(n__a, n__b, n__b) → F(n__a, n__b, n__b)



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
                                    ↳ QDP
                                      ↳ Narrowing
                                        ↳ QDP
                                          ↳ DependencyGraphProof
                                            ↳ QDP
                                              ↳ RuleRemovalProof
                                                ↳ QDP
                                                  ↳ MNOCProof
                                                    ↳ QDP
                                                      ↳ Rewriting
                                                        ↳ QDP
                                                          ↳ UsableRulesProof
                                                            ↳ QDP
                                                              ↳ QReductionProof
                                                                ↳ QDP
                                                                  ↳ Rewriting
QDP
                                                                      ↳ UsableRulesProof

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

F(n__a, n__b, n__b) → F(n__a, n__b, n__b)

The TRS R consists of the following rules:

an__a

The set Q consists of the following terms:

a

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
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
                                    ↳ QDP
                                      ↳ Narrowing
                                        ↳ QDP
                                          ↳ DependencyGraphProof
                                            ↳ QDP
                                              ↳ RuleRemovalProof
                                                ↳ QDP
                                                  ↳ MNOCProof
                                                    ↳ QDP
                                                      ↳ Rewriting
                                                        ↳ QDP
                                                          ↳ UsableRulesProof
                                                            ↳ QDP
                                                              ↳ QReductionProof
                                                                ↳ QDP
                                                                  ↳ Rewriting
                                                                    ↳ QDP
                                                                      ↳ UsableRulesProof
QDP
                                                                          ↳ QReductionProof

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

F(n__a, n__b, n__b) → F(n__a, n__b, n__b)

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

a

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



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ QDP
          ↳ UsableRulesProof
            ↳ QDP
              ↳ Instantiation
                ↳ QDP
                  ↳ UsableRulesProof
                    ↳ QDP
                      ↳ Narrowing
                        ↳ QDP
                          ↳ DependencyGraphProof
                            ↳ QDP
                              ↳ UsableRulesProof
                                ↳ QDP
                                  ↳ Narrowing
                                    ↳ QDP
                                      ↳ Narrowing
                                        ↳ QDP
                                          ↳ DependencyGraphProof
                                            ↳ QDP
                                              ↳ RuleRemovalProof
                                                ↳ QDP
                                                  ↳ MNOCProof
                                                    ↳ QDP
                                                      ↳ Rewriting
                                                        ↳ QDP
                                                          ↳ UsableRulesProof
                                                            ↳ QDP
                                                              ↳ QReductionProof
                                                                ↳ QDP
                                                                  ↳ Rewriting
                                                                    ↳ QDP
                                                                      ↳ UsableRulesProof
                                                                        ↳ QDP
                                                                          ↳ QReductionProof
QDP
                                                                              ↳ NonTerminationProof

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

F(n__a, n__b, n__b) → F(n__a, n__b, n__b)

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:

F(n__a, n__b, n__b) → F(n__a, n__b, n__b)

The TRS R consists of the following rules:none


s = F(n__a, n__b, n__b) evaluates to t =F(n__a, n__b, n__b)

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 F(n__a, n__b, n__b) to F(n__a, n__b, n__b).