SICStus Prolog is fully compliant with the International Standard ISO/IEC 13211-1 (PROLOG: Part 1—General Core) (http://webstore.ansi.org/ansidocstore/product.asp?sku=INCITS%2FISO%2FIEC+13211%2D1%2D1995).
To aid programmers who wish to write standard compliant programs, built-in predicates and arithmetic functors that are part of the ISO Prolog Standard are annotated with [ISO] in this manual.