Left Termination of the query pattern div_in_4(g, g, a, a) w.r.t. the given Prolog program could not be shown:

(0) Obligation:

Clauses:

div(X1, 0, X2, X3) :- failure(a).
div(0, Y, 0, 0) :- no(zero(Y)).
div(X, Y, s(Z), R) :- ','(no(zero(X)), ','(no(zero(Y)), ','(minus(X, Y, U), ','(!, div(U, Y, Z, R))))).
div(X, Y, X4, X) :- ','(no(zero(X)), no(zero(Y))).
minus(X, 0, X).
minus(s(X), s(Y), Z) :- minus(X, Y, Z).
failure(b).
zero(0).
no(X) :- ','(X, ','(!, failure(a))).
no(X5).

Queries:

div(g,g,a,a).

(1) CutEliminatorProof (SOUND transformation)

Eliminated all cuts by simply ignoring them[PROLOG].

(2) Obligation:

Clauses:

div(X1, 0, X2, X3) :- failure(a).
div(0, Y, 0, 0) :- no(zero(Y)).
div(X, Y, s(Z), R) :- ','(no(zero(X)), ','(no(zero(Y)), ','(minus(X, Y, U), div(U, Y, Z, R)))).
div(X, Y, X4, X) :- ','(no(zero(X)), no(zero(Y))).
minus(X, 0, X).
minus(s(X), s(Y), Z) :- minus(X, Y, Z).
failure(b).
zero(0).
no(X) :- ','(X, failure(a)).
no(X5).

Queries:

div(g,g,a,a).