(0) Obligation:

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

f(f(X)) → f(g(f(g(f(X)))))
f(g(f(X))) → f(g(X))

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(X)) → F(g(f(g(f(X)))))
F(f(X)) → F(g(f(X)))
F(g(f(X))) → F(g(X))

The TRS R consists of the following rules:

f(f(X)) → f(g(f(g(f(X)))))
f(g(f(X))) → f(g(X))

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 2 less nodes.

(4) Obligation:

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

F(g(f(X))) → F(g(X))

The TRS R consists of the following rules:

f(f(X)) → f(g(f(g(f(X)))))
f(g(f(X))) → f(g(X))

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

(5) QDPSizeChangeProof (EQUIVALENT transformation)

We used the following order and afs together with the size-change analysis [AAECC05] to show that there are no infinite chains for this DP problem.

Order:Homeomorphic Embedding Order

AFS:
f(x1)  =  f(x1)
g(x1)  =  x1

From the DPs we obtained the following set of size-change graphs:

  • F(g(f(X))) → F(g(X)) (allowed arguments on rhs = {1})
    The graph contains the following edges 1 > 1

We oriented the following set of usable rules [AAECC05,FROCOS05]. none

(6) TRUE