Certification Problem

Input (TPDB TRS_Standard/Strategy_removed_mixed_05/ex5)

The rewrite relation of the following TRS is considered.

f(x) g(f(x)) (1)
g(f(x)) x (2)
g(x) a (3)

Property / Task

Prove or disprove termination.

Answer / Result

No.

Proof (by ttt2 @ termCOMP 2023)

1 Loop

The following loop proves nontermination.

t0 = f(x)
g(f(x))
= t1
where t1 = C[t0σ] and σ = {x/x} and C = g()