10.01.2015 Views

Head-driven Phrase Structure Grammar I

Head-driven Phrase Structure Grammar I

Head-driven Phrase Structure Grammar I

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Basic Idea Typed feature structure HPSG: First glance<br />

Type hierarchy: Subsumption<br />

◮ T : is a finite set of types<br />

◮ ⊑: a partial order defined on T<br />

◮ Reflexive: σ ⊑ σ<br />

◮ Antisymmetric: if σ ⊑ τ and τ ⊑ σ then σ = τ<br />

◮ Transitive: if σ ⊑ ω and ω ⊑ τ then σ ⊑ τ<br />

◮ Subsumption: For types σ, τ ∈ T , σ subsumes or is more<br />

general than or is a supertype of τ, when σ ⊑ τ.<br />

◮ τ is subsumed by or is more specific than or is a subtype of σ.<br />

Example<br />

dolphin elephant salmon<br />

aquatic-animal terrestrial-animal mammal fish<br />

animal<br />

Weiwei Sun <strong>Head</strong>-<strong>driven</strong> <strong>Phrase</strong> <strong>Structure</strong> <strong>Grammar</strong> I 18/61

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!