(0) Obligation:
Q restricted rewrite system:
The TRS R consists of the following rules:
f(f(a, f(a, a)), x) → f(x, f(f(a, a), a))
Q is empty.
(1) DependencyPairsProof (EQUIVALENT transformation)
Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem.
(2) Obligation:
Q DP problem:
The TRS P consists of the following rules:
F(f(a, f(a, a)), x) → F(x, f(f(a, a), a))
F(f(a, f(a, a)), x) → F(f(a, a), a)
The TRS R consists of the following rules:
f(f(a, f(a, a)), x) → f(x, f(f(a, a), a))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(3) DependencyGraphProof (EQUIVALENT transformation)
The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 1 SCC with 1 less node.
(4) Obligation:
Q DP problem:
The TRS P consists of the following rules:
F(f(a, f(a, a)), x) → F(x, f(f(a, a), a))
The TRS R consists of the following rules:
f(f(a, f(a, a)), x) → f(x, f(f(a, a), a))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(5) QDPOrderProof (EQUIVALENT transformation)
We use the reduction pair processor [LPAR04].
The following pairs can be oriented strictly and are deleted.
F(f(a, f(a, a)), x) → F(x, f(f(a, a), a))
The remaining pairs can at least be oriented weakly.
Used ordering: Polynomial interpretation [POLO]:
POL(F(x1, x2)) = x1 + x2
POL(a) = 0
POL(f(x1, x2)) = 1 + x2
The following usable rules [FROCOS05] were oriented:
none
(6) Obligation:
Q DP problem:
P is empty.
The TRS R consists of the following rules:
f(f(a, f(a, a)), x) → f(x, f(f(a, a), a))
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
(7) PisEmptyProof (EQUIVALENT transformation)
The TRS P is empty. Hence, there is no (P,Q,R) chain.
(8) TRUE