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(x, y, f(z, u, v)) → f(f(x, y, z), u, f(x, y, v))
Q is empty.
↳ QTRS
↳ DependencyPairsProof
Q restricted rewrite system:
The TRS R consists of the following rules:
f(x, y, f(z, u, v)) → f(f(x, y, z), u, f(x, y, v))
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(x, y, f(z, u, v)) → F(x, y, z)
F(x, y, f(z, u, v)) → F(f(x, y, z), u, f(x, y, v))
F(x, y, f(z, u, v)) → F(x, y, v)
The TRS R consists of the following rules:
f(x, y, f(z, u, v)) → f(f(x, y, z), u, f(x, y, v))
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(x, y, f(z, u, v)) → F(x, y, z)
F(x, y, f(z, u, v)) → F(f(x, y, z), u, f(x, y, v))
F(x, y, f(z, u, v)) → F(x, y, v)
The TRS R consists of the following rules:
f(x, y, f(z, u, v)) → f(f(x, y, z), u, f(x, y, v))
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(x, y, f(z, u, v)) → F(x, y, z)
F(x, y, f(z, u, v)) → F(f(x, y, z), u, f(x, y, v))
F(x, y, f(z, u, v)) → F(x, y, v)
The TRS R consists of the following rules:
f(x, y, f(z, u, v)) → f(f(x, y, z), u, f(x, y, v))
s = F(x, y, f(z, u, v)) evaluates to t =F(f(x, y, z), u, f(x, y, v))
Thus s starts an infinite chain as s semiunifies with t with the following substitutions:
- Semiunifier: [ ]
- Matcher: [z / x, u / y, y / u, x / f(x, y, z)]
Rewriting sequence
The DP semiunifies directly so there is only one rewrite step from F(x, y, f(z, u, v)) to F(f(x, y, z), u, f(x, y, v)).