(0) Obligation:

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

f(f(y, z), f(x, f(a, x))) → f(f(f(a, z), f(x, a)), f(a, y))

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(y, z), f(x, f(a, x))) → F(f(f(a, z), f(x, a)), f(a, y))
F(f(y, z), f(x, f(a, x))) → F(f(a, z), f(x, a))
F(f(y, z), f(x, f(a, x))) → F(a, z)
F(f(y, z), f(x, f(a, x))) → F(x, a)
F(f(y, z), f(x, f(a, x))) → F(a, y)

The TRS R consists of the following rules:

f(f(y, z), f(x, f(a, x))) → f(f(f(a, z), f(x, a)), f(a, y))

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 4 less nodes.

(4) Obligation:

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

F(f(y, z), f(x, f(a, x))) → F(f(f(a, z), f(x, a)), f(a, y))

The TRS R consists of the following rules:

f(f(y, z), f(x, f(a, x))) → f(f(f(a, z), f(x, a)), f(a, y))

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