Certification Problem

Input (TPDB TRS_Standard/Strategy_removed_mixed_05/n001)

The rewrite relation of the following TRS is considered.

h(f(f(x))) h(f(g(f(x)))) (1)
f(g(f(x))) f(f(x)) (2)

Property / Task

Prove or disprove termination.

Answer / Result

No.

Proof (by AProVE @ termCOMP 2023)

1 Looping derivation

There is a looping derivation.

h f f+ ε h f f ε

The derivation can be derived as follows.