SWI-Prolog -- call/1

Availability:built-in

[ISO]call(:Goal)

Call Goal. This predicate is normally used for goals that are not known at compile time. For example, the Prolog toplevel essentially performs read(Goal), call(Goal). Also a meta predicates such as ignore/1 are defined using call:

ignore(Goal) :- call(Goal), !.
ignore(_).

Note that a plain variable as a body term acts as call/1 and the above is equivalent to the code below. SWI-Prolog produces the same code for these two progams and listing/1 prints the program above.

ignore(Goal) :- Goal, !.
ignore(_).

Note that call/1 restricts the scope of the cut (!/0). A cut inside Goal only affects choice points created by Goal.