Certification Problem

Input (TPDB TRS_Relative/Relative_05/rt3-6)

The relative rewrite relation R/S is considered where R is the following TRS

b(a(x)) a(b(x)) (1)

and S is the following TRS.

a(x) a(a(x)) (2)
b(x) b(b(x)) (3)

Property / Task

Prove or disprove termination.

Answer / Result

No.

Proof (by ttt2 @ termCOMP 2023)

1 Loop

The following loop proves that R/S is not relative terminating.

t0 = b(a(x18))
S b(b(a(x18)))
R b(a(b(x18)))
= t2
where t2 = t0σ and σ = {x18/b(x18)}