SWI-Prolog provides an online help system that covers this manual. If
the XPCE graphics system is available, online help opens a graphical
window. Otherwise the documentation is shown in the Prolog console. The
help system is controlled by the predicates below. Note that this help
system only covers the core SWI-Prolog manual. The website8http://www.swi-prolog.org
provides an integrated manual that covers the core system as well as all
standard extension packages. It is possible to install the SWI-Prolog
website locally by cloning the website repository
and following the instructions in the
- Equivalent to
- Show specified part of the manual. What is one of:
<Name>/<Arity> Give help on specified predicate <Name> Give help on named predicate with any arity or C interface function with that name <Section> Display specified section. Section numbers are dash-separated numbers:
2-3refers to section 2.3 of the manual. Section numbers are obtained using apropos/1.
Give help on predicate assert
Display section 3.4 of the manual
Give help on interface function PL_retry()
- Display all predicates, functions and sections that have Pattern
in their name or summary description. Lowercase letters in
Pattern also match a corresponding uppercase letter. Example:
Display predicates, functions and sections that have `file' (or `File', etc.) in their summary description.
- Give an explanation on the given `object'. The argument may be any Prolog data object. If the argument is an atom, a term of the form Name/Arity or a term of the form Module:Name/Arity, explain/1 describes the predicate as well as possible references to it. See also gxref/0.
- explain(+ToExplain, -Explanation)
- Unify Explanation with an explanation for ToExplain. Backtracking yields further explanations.