Certification Problem

Input (TPDB TRS_Outermost/Strategy_outermost_added_08/ExIntrod_GM01_L)

The rewrite relation of the following TRS is considered.

tail(cons(X)) L (1)
incr(nil) nil (2)
incr(cons(X)) cons(s(X)) (3)
adx(nil) nil (4)
adx(cons(X)) incr(cons(X)) (5)
nats adx(zeros) (6)
zeros cons(0) (7)
head(cons(X)) X (8)
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 = tail(cons(X))
tail(cons(X))
= t1
where t1 = t0σ and σ = {X/X}