Defaults and lexical prototypes
Malouf R.
Inheritance plays several distinct but crucial roles in the representation of linguistic information in Head-Driven Phrase Structure Grammar and other constraint-based frameworks. The primary use of inheritance is in the definition of the type signature, a specification of what counts as a well-formed linguistic object. In more recent developments of the theory, inheritance is also used to express substantive linguistic generalizations. This latter use is quite different from the original problem that inheritance was introduced into HPSG to solve, and there are other knowledge representation devices that might be more appropriate. In particular, delegation can also be used to express linguistic generalizations. The use of delegation can simplify HPSG analyses of some phenomena and can also clarify some of the issues that arise in the use default unification.