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:

c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1)))))))

Q is empty.


QTRS
  ↳ QTRS Reverse
  ↳ Strip Symbols Proof
  ↳ QTRS Reverse
  ↳ Overlay + Local Confluence

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

c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1)))))))

Q is empty.

We have reversed the following QTRS:
The set of rules R is

c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1)))))))

The set Q is empty.
We have obtained the following QTRS:

a(b(a(c(x)))) → a(c(c(b(a(b(a(x)))))))

The set Q is empty.

↳ QTRS
  ↳ QTRS Reverse
QTRS
  ↳ Strip Symbols Proof
  ↳ QTRS Reverse
  ↳ Overlay + Local Confluence

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

a(b(a(c(x)))) → a(c(c(b(a(b(a(x)))))))

Q is empty.

We were given the following TRS:

c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1)))))))

By stripping symbols from the only rule of the system, we obtained the following TRS:

c(a(b(x))) → a(b(a(b(c(c(x))))))


↳ QTRS
  ↳ QTRS Reverse
  ↳ Strip Symbols Proof
QTRS
  ↳ QTRS Reverse
  ↳ Overlay + Local Confluence

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

c(a(b(x))) → a(b(a(b(c(c(x))))))

Q is empty.

We have reversed the following QTRS:
The set of rules R is

c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1)))))))

The set Q is empty.
We have obtained the following QTRS:

a(b(a(c(x)))) → a(c(c(b(a(b(a(x)))))))

The set Q is empty.

↳ QTRS
  ↳ QTRS Reverse
  ↳ Strip Symbols Proof
  ↳ QTRS Reverse
QTRS
      ↳ Strip Symbols Proof
  ↳ Overlay + Local Confluence

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

a(b(a(c(x)))) → a(c(c(b(a(b(a(x)))))))

Q is empty.

We were given the following TRS:

a(b(a(c(x)))) → a(c(c(b(a(b(a(x)))))))

By stripping symbols from the only rule of the system, we obtained the following TRS:

b(a(c(x))) → c(c(b(a(b(a(x))))))


↳ QTRS
  ↳ QTRS Reverse
  ↳ Strip Symbols Proof
  ↳ QTRS Reverse
    ↳ QTRS
      ↳ Strip Symbols Proof
QTRS
  ↳ Overlay + Local Confluence

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

b(a(c(x))) → c(c(b(a(b(a(x))))))

Q is empty.

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

↳ QTRS
  ↳ QTRS Reverse
  ↳ Strip Symbols Proof
  ↳ QTRS Reverse
  ↳ Overlay + Local Confluence
QTRS
      ↳ DependencyPairsProof

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

c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1)))))))

The set Q consists of the following terms:

c(a(b(a(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:

C(a(b(a(x1)))) → C(c(a(x1)))
C(a(b(a(x1)))) → C(a(x1))

The TRS R consists of the following rules:

c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1)))))))

The set Q consists of the following terms:

c(a(b(a(x0))))

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

↳ QTRS
  ↳ QTRS Reverse
  ↳ Strip Symbols Proof
  ↳ QTRS Reverse
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
QDP
          ↳ MNOCProof

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

C(a(b(a(x1)))) → C(c(a(x1)))
C(a(b(a(x1)))) → C(a(x1))

The TRS R consists of the following rules:

c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1)))))))

The set Q consists of the following terms:

c(a(b(a(x0))))

We have to consider all minimal (P,Q,R)-chains.
We use the modular non-overlap check [17] to decrease Q to the empty set.

↳ QTRS
  ↳ QTRS Reverse
  ↳ Strip Symbols Proof
  ↳ QTRS Reverse
  ↳ Overlay + Local Confluence
    ↳ QTRS
      ↳ DependencyPairsProof
        ↳ QDP
          ↳ MNOCProof
QDP
              ↳ NonTerminationProof

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

C(a(b(a(x1)))) → C(c(a(x1)))
C(a(b(a(x1)))) → C(a(x1))

The TRS R consists of the following rules:

c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1)))))))

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:

C(a(b(a(x1)))) → C(c(a(x1)))
C(a(b(a(x1)))) → C(a(x1))

The TRS R consists of the following rules:

c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1)))))))


s = C(c(a(b(c(c(a(b(a(x1'))))))))) evaluates to t =C(c(a(b(c(c(a(b(a(b(c(c(a(b(c(c(a(x1')))))))))))))))))

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




Rewriting sequence

C(c(a(b(c(c(a(b(a(x1')))))))))C(c(a(b(c(a(b(a(b(c(c(a(x1'))))))))))))
with rule c(a(b(a(x1'')))) → a(b(a(b(c(c(a(x1''))))))) at position [0,0,0,0,0] and matcher [x1'' / x1']

C(c(a(b(c(a(b(a(b(c(c(a(x1'))))))))))))C(c(a(b(a(b(a(b(c(c(a(b(c(c(a(x1')))))))))))))))
with rule c(a(b(a(x1)))) → a(b(a(b(c(c(a(x1))))))) at position [0,0,0,0] and matcher [x1 / b(c(c(a(x1'))))]

C(c(a(b(a(b(a(b(c(c(a(b(c(c(a(x1')))))))))))))))C(a(b(a(b(c(c(a(b(a(b(c(c(a(b(c(c(a(x1'))))))))))))))))))
with rule c(a(b(a(x1'')))) → a(b(a(b(c(c(a(x1''))))))) at position [0] and matcher [x1'' / b(a(b(c(c(a(b(c(c(a(x1'))))))))))]

C(a(b(a(b(c(c(a(b(a(b(c(c(a(b(c(c(a(x1'))))))))))))))))))C(c(a(b(c(c(a(b(a(b(c(c(a(b(c(c(a(x1')))))))))))))))))
with rule C(a(b(a(x1)))) → C(c(a(x1)))

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.