This chapter gives a short overview of the Extended Backus-Naur Form (EBNF) notation, which is frequently used in this document to describe file formats and syntax rules. A short introduction to EBNF is presented.
ProcDecl = PROCEDURE "(" ArgList ")". ArgList = Expression {"," Expression}. Expression = Term ("*"|"/") Term. Term = Factor AddOp Factor. AddOp = "+"|"-". Factor = (["-"] Number)|"(" Expression ")".
The EBNF language is a formalism that can be used to express the syntax of context-free languages. The EBNF grammar consists of a rule set called - productions of the form:
LeftHandSide = RightHandSide.
The left-hand side is a non-terminal symbol. The right-hand side describes how it is composed.
EBNF consists of the symbols discussed in the sections that follow.