1. Extended Backus-Naur Form Any variation on the basic Backus-Naur Form BNF meta-syntax notation with some of the following additional constructs: square brackets "[. . ]" surrounding optional items, suffix "*" for Kleene closure a sequence of zero or more of an item, suffix "+" for one or more of an item, curly brackets enclosing a list of alternatives, and super/subscripts indicating between n and m occurrences. All these constructs can be expressed in plain BNF using extra productions and have been added for readability and succinctness.
extended backus-naur form |
