3 How to Run Prolog

SICStus Prolog offers the user an interactive programming environment with tools for incrementally building programs, debugging programs by following their executions, and modifying parts of programs without having to start again from scratch.

The source text of a Prolog program is normally created in a file or a number of files, using the SPIDER IDE (see SPIDER) or GNU Emacs (see Emacs Interface). Other text editors can also be used but will typically not contain any Prolog-specific functionality.

SICStus can then be instructed to load the program from these source files; typically by compiling the file, i.e. converting the file to an efficient internal representation. Alternatively, the Prolog interpreter can be instructed to read in programs from these files without such conversion; this is called consulting the file (sometimes “consulting” is used to denote both these ways of loading program from its source files).