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If X is instantiated to a term that would be acceptable as the
body of a clause, then the goal call(X)
is executed exactly as
if that term appeared textually in place of the call(X)
,
except the scope of any cut occurring in X is limited to the
execution of X. That is, the cut does not “propagate” into the
clause in which call(X)
occurs. If X is not
properly instantiated, then an error exception is raised as described in
ref-sem-exc.
In release 4, call/1
has been generalized to
call/N
of any arity N between 1 and 255: the first
argument is treated as template, which should be augmented by the
remaining arguments, giving the goal to call. For example, the goal
call(p(X),Y,Z)
is equivalent to the goal p(X,Y,Z)
.
Note in particular that the first argument does not need to be an atom.