(0) Obligation:
Q restricted rewrite system:
The TRS R consists of the following rules:
f(a, f(f(a, x), a)) → f(f(a, f(a, x)), 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(a, f(f(a, x), a)) → F(f(a, f(a, x)), a)
F(a, f(f(a, x), a)) → F(a, f(a, x))
The TRS R consists of the following rules:
f(a, f(f(a, x), a)) → f(f(a, f(a, x)), 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(a, f(f(a, x), a)) → F(a, f(a, x))
The TRS R consists of the following rules:
f(a, f(f(a, x), a)) → f(f(a, f(a, x)), 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(a, f(f(a, x), a)) → F(a, f(a, x))
The remaining pairs can at least be oriented weakly.
Used ordering: Lexicographic path order with status [LPO].
Quasi-Precedence:
[F2, a, f2]
Status:
F2: [2,1]
a: []
f2: [2,1]
The following usable rules [FROCOS05] were oriented:
f(a, f(f(a, x), a)) → f(f(a, f(a, x)), a)
(6) Obligation:
Q DP problem:
P is empty.
The TRS R consists of the following rules:
f(a, f(f(a, x), a)) → f(f(a, f(a, x)), 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