8.6 Core Expression Language
This clause defines a subset of the expression language called the core expression language.  In the core expression language, only those expressions and definitions allowed by the productions in this clause are permitted, and only those procedures with prototypes in this clause are available.  Any expression or definition that is valid in the core expression language has the same meaning that it does in the full expression language.
8.6.1 Syntax
8.6.2 Procedures