2.7  How do I use ECLⁱPS^e libraries in my programs?

A number of files containing library predicates are supplied with the ECLⁱPS^e system. They are usually installed in an ECLⁱPS^e library directory. These predicates are either loaded automatically by ECLⁱPS^e or may be loaded “by hand”.

During the execution of an ECLⁱPS^e program, the system may dynamically load files containing library predicates. When this happens, the user is informed by a compilation or loading message. It is possible to explicitly force this loading to occur by use of the lib/1 or use_module/1 predicates. E.g. to load the library called lists, use one of the following goals:

:- lib(lists)
:- use_module(library(lists))

This will load the library file unless it has been already loaded. In particular, a program can ensure that a given library is loaded when it is compiled, by including an appropriate directive in the source, e.g. :- lib(lists).