Online help provides a fast lookup and browsing facility to this manual. The online manual can show predicate definitions as well as entire sections of the manual.
The online help is displayed from the file library('MANUAL').
The file
library(helpidx) provides an index into this file. library('MANUAL')
is created from the LaTeX sources with a modified version of
dvitty, using overstrike for printing bold text and underlining
for rendering italic text. XPCE is shipped with
library(swi_help), presenting the information from the
online help in a hypertext window. The Prolog flag write_help_with_overstrike
controls whether or not help/1
writes its output using overstrike to realise bold and underlined output
or not. If this Prolog flag is not set it is initialised by the help
library to true if the TERM variable equals xterm
and false otherwise. If this default does not satisfy you,
add the following line to your personal startup file (see section
2.2):
:- set_prolog_flag(write_help_with_overstrike, true).
help(help/1).| <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: 2-3 refers to
section 2.3 of the manual. Section numbers are obtained using apropos/1. |
Examples:
?- help(assert). | Give help on predicate assert |
?- help(3-4). | Display section 3.4 of the manual |
?- help('PL_retry'). | Give help on interface function PL_retry() |
See also apropos/1, and the SWI-Prolog home page at http://www.swi-prolog.org, which provides a FAQ, an HTML version of manual for online browsing and HTML and PDF versions for downloading.
?- apropos(file). | Display predicates, functions and sections that have `file' (or `File', etc.) in their summary description. |