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(a, X) → f(X, X)
ca
cb

Q is empty.


QTRS
  ↳ DependencyPairsProof

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

f(a, X) → f(X, X)
ca
cb

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:

F(a, X) → F(X, X)

The TRS R consists of the following rules:

f(a, X) → f(X, X)
ca
cb

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

↳ QTRS
  ↳ DependencyPairsProof
QDP
      ↳ NonTerminationProof

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

F(a, X) → F(X, X)

The TRS R consists of the following rules:

f(a, X) → f(X, X)
ca
cb

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(a, X) → F(X, X)

The TRS R consists of the following rules:

f(a, X) → f(X, X)
ca
cb


s = F(a, X) evaluates to t =F(X, X)

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(a, a) to F(a, a).