ABSTRACT

Unification formalism by itself is not a grammatical theory but a formalism in which different grammatical theories can be instantiated. The actual "unification" used may range from strict logical unification to more or less arbitrarily powerful pattern matching with many other variants aimed at capturing specific types of linguistic regularity. The compilation process serves several purposes: the practical one of ensuring that you can actually do something with the grammar parse, or generate sentences. The standard Context-Free Grammar based formalisms can do all the computations that a unification-based formalism can do and vice versa; however, the semantics of the formalism is not always well understood. To the extent a formalism is declarative it can be neutral between analysis and production. The processes which manipulate unification formalisms may or may not differ for analysis and production. Neutrality between analysis and production is a property shared by a variety of grammatical formalisms.