Certification Problem

Input (TPDB TRS_Outermost/Strategy_outermost_added_08/Ex6_9_Luc02c)

The rewrite relation of the following TRS is considered.

2nd(cons1(X,cons(Y,Z))) Y (1)
2nd(cons(X,X1)) 2nd(cons1(X,X1)) (2)
from(X) cons(X,from(s(X))) (3)
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 = from(X)
cons(X,from(s(X)))
= t1
where t1 = C[t0σ] and σ = {X/s(X)} and C = cons(X,)