Grammar Overrides refer to nonterminal modifications or extensions to a fixed base grammar for the purpose of extending the language or customizing the parse to the task (Agile Parsing^?). Grammar Overrides are most obvious and convenient in TXL, which has an explicit feature for implementing them, but are a general concept used in many source transformation systems. They can be implemented any number of ways including using Grammar Adaptation^?, Grammar Transformation^? or by hand using cloning of the original base grammmar.

-- JamesCordy - 10 Oct 2005