Dominance Constraints in Context Uni
نویسندگان
چکیده
Tree descriptions based on dominance constraints are popular in several areas of computational linguistics including syntax, semantics , and discourse. Tree descriptions in the language of context unii-cation have attracted some interest in uniication and rewriting theory. Recently, dominance constraints and context uniication have both been used in diierent underspeciied approaches to the semantics of scope, parallelism, and their interaction. This raises the question whether both description languages are related. In this paper, we show for a rst time that dominance constraints can be expressed in context uniication. We also prove that dominance constraints extended with parallelism constraints are equal in expressive power to context uniication.
منابع مشابه
Electricity Procurement for Large Consumers with Second Order Stochastic Dominance Constraints
This paper presents a decision making approach for mid-term scheduling of large industrial consumers based on the recently introduced class of Stochastic Dominance (SD)- constrained stochastic programming. In this study, the electricity price in the pool as well as the rate of availability (unavailability) of the generating unit (forced outage rate) is considered as uncertain parameters. Th...
متن کاملDominance constraints in stratified context unification
We express dominance constraints in the once-only nesting fragment of stratified context unification, which therefore is NP-complete.
متن کاملOn Equality Up-to Constraints over Finite Trees, Context Uni cation, and One-Step Rewriting
متن کامل
On Equality Up-to Constraints over Finite Trees, Context Unification, and One-Step Rewriting
We introduce equality up-to constraints over nite trees and investigate their expressiveness. Equality up-to constraints subsume equality constraints, subtree constraints, and one-step rewriting constraints. We establish a close correspondence between equality up-to constraints over nite trees and context uniication. Context uniication subsumes string uniication and is subsumed by linear second...
متن کاملParsing by Successive Approximation
It is proposed to parse feature structure-based grammars in several steps. Each step is aimed to eliminate as many invalid analyses as possible as e ciently as possible. To this end the set of feature constraints is divided into three subsets, a set of context-free constraints, a set of ltering constraints and a set of structure-building constraints, which are solved in that order. The best pro...
متن کامل