(0) Obligation:

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

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

Q is empty.

(1) Overlay + Local Confluence (EQUIVALENT transformation)

The TRS is overlay and locally confluent. By [NOC] we can switch to innermost.

(2) Obligation:

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

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

The set Q consists of the following terms:

f(f(f(a, x0), x1), x2)
f(f(b, x0), x1)
f(c, x0)

(3) DependencyPairsProof (EQUIVALENT transformation)

Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem.

(4) Obligation:

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

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

The TRS R consists of the following rules:

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

The set Q consists of the following terms:

f(f(f(a, x0), x1), x2)
f(f(b, x0), x1)
f(c, x0)

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