(0) Obligation:

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

h(f(x, y)) → f(y, f(h(h(x)), a))

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:

h(f(x, y)) → f(y, f(h(h(x)), a))

The set Q consists of the following terms:

h(f(x0, x1))

(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:

H(f(x, y)) → H(h(x))
H(f(x, y)) → H(x)

The TRS R consists of the following rules:

h(f(x, y)) → f(y, f(h(h(x)), a))

The set Q consists of the following terms:

h(f(x0, x1))

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