Certification Problem

Input (TPDB TRS_Outermost/Strategy_outermost_added_08/Ex1_Luc04b_L)

The rewrite relation of the following TRS is considered.

tail(cons(X)) XS (1)
nats cons(0) (2)
pairs cons(0) (3)
odds incr(pairs) (4)
incr(cons(X)) cons(s(X)) (5)
head(cons(X)) X (6)
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}