/* As a GNU extension we support an expanded level-2 expression syntax.
Via this extension we support (arbitrary) nesting of unary plus and
minus operations following unary and binary operators, such as **.
- The grammar of section 7.1.1.3 is effectively rewitten as:
+ The grammar of section 7.1.1.3 is effectively rewritten as:
R704 mult-operand is level-1-expr [ power-op ext-mult-operand ]
R704' ext-mult-operand is add-op ext-mult-operand