\+/1¶
Description¶
\+ Goal
Not-provable meta-predicate. True iff call(Goal)
is false. This
built-in meta-predicate is declared as a private method and thus cannot
be used as a message to an object.
Modes and number of proofs¶
\+ +callable - zero_or_one
Errors¶
Goal is a variable:
instantiation_error
Goal is neither a variable nor a callable term:
type_error(callable, Goal)