(0) Obligation:
Clauses:
list([]).
list(X) :- ','(no(empty(X)), ','(tail(X, T), list(T))).
tail([], []).
tail(.(X, Xs), Xs).
empty(X).
no(X) :- ','(X, ','(!, failure(a))).
no(X1).
failure(b).
Query: list(g)
(1) PrologToPiTRSViaGraphTransformerProof (SOUND transformation)
Transformed Prolog program to (Pi-)TRS.
(2) Obligation:
Pi-finite rewrite system:
The TRS R consists of the following rules:
listA_in_g([]) → listA_out_g([])
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:
listA_in_g([]) → listA_out_g([])
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:
listA_in_g([]) → listA_out_g([])
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