7 Standard Prolog Compliance

SICStus 3.8 supports standard Prolog, adhering to 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). At the same time it also supports programs written in earlier versions of SICStus. This is achieved by introducing two execution modes iso and sicstus. Users can change between the modes using the Prolog flag language. Main issues: