Certification Problem

Input (TPDB TRS_Outermost/Strategy_outermost_added_08/ExIntrod_GM01)

The rewrite relation of the following TRS is considered.

incr(nil) nil (1)
incr(cons(X,L)) cons(s(X),incr(L)) (2)
adx(nil) nil (3)
adx(cons(X,L)) incr(cons(X,adx(L))) (4)
nats adx(zeros) (5)
zeros cons(0,zeros) (6)
head(cons(X,L)) X (7)
tail(cons(X,L)) L (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 = zeros
cons(0,zeros)
= t1
where t1 = C[t0] and C = cons(0,)