/1¶

(G -> H)

Call goal H once per each solution of goal G.

The built-in *->3 is usually called from within a disjunction. It performs similar to ->//33, with the difference that it will backtrack over the test goal. Consider the following small data-base:

 a(1). b(a). c(x).
 a(2). b(b). c(y).

Execution of an *->//33 query will proceed as follows:

 ?- (a(X)->b(Y);c(Z)).
 X = 1,
 Y = a ? ;
 X = 1,
 Y = b ? ;
 X = 2,
 Y = a ? ;
 X = 2,
 Y = b ? ;
 no

The system will backtrack over the two solutions for a//11and the two solutions for @ref U60UbU2fU_1 "b//1"1, generating four solutions.

Cuts are allowed inside the first goal __G__, but they will only prune over __G__.

If you want __G__ to be deterministic you should use if-then-else, as it is both more efficient and more portable.