By default the result of help/1
is sent through a pager such as
less. This behaviour is controlled by the following:
help_pager, which can be set to one of the following values:
PAGERor otherwise tries to find the
program_name(Arg, ...). For example,
less('-r')would be the default. Note that the program name can be an absolute path if single quotes are used.
topics(s)to give help for. Notations for What are:
If an exact match fails this predicates attempts fuzzy matching and, when successful, display the results headed by a warning that the matches are based on fuzzy matching.
If possible, the results are sent through a pager such as the
less program. This behaviour is controlled by the Prolog
help_pager. See section level documentation.
non_terminal. For example:
?- apropos(c:close). ?- apropos(f:min).
library(explain) describes prolog-terms. The most
useful functionality is its cross-referencing function.
?- explain(subset(_,_)). "subset(_, _)" is a compound term Referenced from 2-th clause of lists:subset/2 Referenced from 46-th clause of prolog_xref:imported/3 Referenced from 68-th clause of prolog_xref:imported/3 lists:subset/2 is a predicate defined in /staff/jan/lib/pl-5.6.17/library/lists.pl:307 Referenced from 2-th clause of lists:subset/2 Possibly referenced from 2-th clause of lists:subset/2
Note that the help-tool for XPCE provides a nice graphical cross-referencer.
Name/Arityor a term of the form
Module:Name/Arity, explain/1 describes the predicate as well as possible references to it. See also gxref/0.