The Head-Driven Phrase Structure Grammar (HPSG) is a grammar theory developed by Pollard and Sag (1985). It uses a uniform formalism and is organized in a modular way which makes it attractive for Natural language processing.
... the town is $68,125, and the median income for a family is $71,726. Males have a median income of $51,332 versus $32,188 for females. The per capita income for the town is ...