8 Built-In Predicates
SICStus Prolog provides a wide range of built-in predicates to
perform all kinds of tasks; see the Table of Contents.
It is not possible to redefine built-in predicates. An attempt to
do so will raise an exception. See Pred Summary.
When introducing a built-in predicate, we shall present its usage
with a mode spec, and optionally with an annotation containing one
or more of:
- The predicate complies with the ISO Prolog Standard.
- ISO only
- The predicate variant described complies with the ISO Prolog Standard
and is valid in the
iso execution mode only.
- SICStus only
- The predicate variant described is valid in the
- A declaration that can't be redefined as a predicate.
- The predicate is not available in runtime systems.
- The predicate is an extendible predicate.
- The predicate is a hook predicate.
- The predicate is a hookable predicate.
- The predicate is obsolescent and should be avoided in new code.
- A reserved construct that can't be defined as a predicate.
The following descriptions of the built-in predicates are grouped
according to the above categorization of their tasks.