Certification Problem

Input (TPDB TRS_Outermost/Strategy_outermost_added_08/#4.15)

The rewrite relation of the following TRS is considered.

f(0,1,g(x,y),z) f(g(x,y),g(x,y),g(x,y),h(x)) (1)
g(0,1) 0 (2)
g(0,1) 1 (3)
h(g(x,y)) h(x) (4)
The evaluation strategy is outermost

Property / Task

Prove or disprove termination.

Answer / Result

No.

Proof (by AProVE @ termCOMP 2023)

1 Loop

The following loop proves nontermination.

t0 = f(g(0,1),g(0,1),g(0,1),h(0))
f(g(0,1),1,g(0,1),h(0))
f(0,1,g(0,1),h(0))
f(g(0,1),g(0,1),g(0,1),h(0))
= t3
where t3 = t0