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Chapter 2: Building Discourse Representations. November 14, 2007 Matt Gerber. DRS Construction. Claim: DRT is a flexible theory compatible with a range of construction strategies DRS threading Rehash of the SCA -DRSs -abstraction approach Underspecified DRSs Hole semantics.
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Chapter 2: Building Discourse Representations November 14, 2007 Matt Gerber
DRS Construction • Claim: DRT is a flexible theory compatible with a range of construction strategies • DRS threading • Rehash of the SCA • -DRSs • -abstraction approach • Underspecified DRSs • Hole semantics
DRS threading • A different perspective on the standard construction algorithm • Syntactic constituents are “threaded” through the current DRS
DRS threading • Simple IV “dances”: • Key: input/output DRS, the difference between the two being the semantic contribution of the current node
DRS threading • “Mia dances”: • Unary branching rules add no semantic content
DRS threading • “Every gimp runs”: antecedent formation
DRS threading • “Every gimp runs”: DRS completion
-DRSs • Parallel approach to sentence semantics for DRT • Create DRSs through functional application
-DRSs • Addition to DRS language: the merge operation • Union of discourse referents and conditions
-DRSs • Coordination caveat: “A woman walks and a woman talks.” *
-DRSs • Some lexical entries (nouns):
-DRSs • Some lexical entries (determiners): Previously:
-DRSs • Some lexical entries (verbs):
Underspecified DRSs • Review: hole semantics • “Every boxer loves a woman”
Underspecified DRSs • Review: hole semantics • Valid plugging: any that produces a formula tree and respects the dominance constraints
Underspecified DRSs • Review: hole semantics • “Every boxer loves a woman” (weaker) Universal quantifier out-scopes existential quantifier
Underspecified DRSs • Review: hole semantics • “Every boxer loves a woman” (stronger) Existential quantifier out-scopes universal quantifier
Underspecified DRSs • Example: “Every boxer loves a woman” • Available DRS “chunks”:
Underspecified DRSs • Example: “Every boxer loves a woman” • Dominance constraints • : ensures the verb is out-scoped by the two NP DRSs
Underspecified DRSs • Example: “Every boxer loves a woman” Possible pluggings:
Underspecified DRSs • Example: “Every boxer loves a woman” Possible pluggings: Plugging P1 Plugging P2