(0) Obligation:
Clauses:
goal :- ','(lte(X, s(s(s(s(0))))), even(X)).
lte(0, Y).
lte(X, s(Y)) :- ','(no(zero(X)), ','(p(X, P), lte(P, Y))).
even(0).
even(s(s(X))) :- even(X).
p(0, 0).
p(s(X), X).
zero(0).
no(X) :- ','(X, ','(!, failure(a))).
no(X1).
failure(b).
Query: goal()
(1) PrologToPiTRSViaGraphTransformerProof (SOUND transformation)
Transformed Prolog program to (Pi-)TRS.
(2) Obligation:
Pi-finite rewrite system:
The TRS R consists of the following rules:
goalA_in_ → goalA_out_
Pi is empty.
(3) DependencyPairsProof (EQUIVALENT transformation)
Using Dependency Pairs [AG00,LOPSTR] we result in the following initial DP problem:
Pi DP problem:
P is empty.
The TRS R consists of the following rules:
goalA_in_ → goalA_out_
Pi is empty.
We have to consider all (P,R,Pi)-chains
(4) Obligation:
Pi DP problem:
P is empty.
The TRS R consists of the following rules:
goalA_in_ → goalA_out_
Pi is empty.
We have to consider all (P,R,Pi)-chains
(5) PisEmptyProof (EQUIVALENT transformation)
The TRS P is empty. Hence, there is no (P,R,Pi) chain.
(6) YES