2.6 Online Help

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_ustar  rootroot



SWI-Prolog 5.6.59 Reference Manual









7 CHR: Constraint Handling Rules

This chapter is written by Tom Schrijvers, K.U. Leuven, and adjustments by Jan Wielemaker.

The CHR system of SWI-Prolog is the K.U.Leuven CHR system. The runtime environment is written by Christian Holzbaur and Tom Schrijvers while the compiler is written by Tom Schrijvers. Both are integrated with SWI-Prolog and licensed under compatible conditions with permission from the authors.

The main