181 research outputs found
Linear Logic for Meaning Assembly
Semantic theories of natural language associate meanings with utterances by
providing meanings for lexical items and rules for determining the meaning of
larger units given the meanings of their parts. Meanings are often assumed to
combine via function application, which works well when constituent structure
trees are used to guide semantic composition. However, we believe that the
functional structure of Lexical-Functional Grammar is best used to provide the
syntactic information necessary for constraining derivations of meaning in a
cross-linguistically uniform format. It has been difficult, however, to
reconcile this approach with the combination of meanings by function
application. In contrast to compositional approaches, we present a deductive
approach to assembling meanings, based on reasoning with constraints, which
meshes well with the unordered nature of information in the functional
structure. Our use of linear logic as a `glue' for assembling meanings allows
for a coherent treatment of the LFG requirements of completeness and coherence
as well as of modification and quantification.Comment: 19 pages, uses lingmacros.sty, fullname.sty, tree-dvips.sty,
latexsym.sty, requires the new version of Late
Indeterminacy by underspecification
We examine the formal encoding of feature indeterminacy, focussing on case indeterminacy as an exemplar of the phenomenon. Forms that are indeterminately specified for the value of a feature can simultaneously satisfy conflicting requirements on that feature and thus are a challenge to constraint-based formalisms which model the compatibility of information carried by linguistic items by combining or integrating that information. Much previous work in constraint-based formalisms has sought to provide an analysis of feature indeterminacy by departing in some way from ‘vanilla’ assumptions either about feature representations or about how compatibility is checked by integrating information from various sources. In the present contribution we argue instead that a solution to the range of issues posed by feature indeterminacy can be provided in a ‘vanilla’ feature-based approach which is formally simple, does not postulate special structures or objects in the representation of case or other indeterminate features, and requires no special provision for the analysis of coordination. We view the value of an indeterminate feature such as case as a complex and possibly underspecified feature structure. Our approach correctly allows for incremental and monotonic refinement of case requirements in particular contexts. It uses only atomic boolean-valued features and requires no special mechanisms or additional assumptions in the treatment of coordination or other phenomena to handle indeterminacy. Our account covers the behaviour of both indeterminate arguments and indeterminate predicates, that is, predicates placing indeterminate requirements on their arguments.</jats:p
Interactions of scope and ellipsis
Systematic semantic ambiguities result from the interaction of the two operations that are involved in resolving ellipsis in the presence of scoping elements such as quantifiers and intensional operators: scope determination for the scoping elements and resolution of the elided relation. A variety of problematic examples previously noted - by Sag, Hirschbüihler, Gawron and Peters, Harper, and others - all have to do with such interactions. In previous work, we showed how ellipsis resolution can be stated and solved in equational terms. Furthermore, this equational analysis of ellipsis provides a uniform framework in which interactions between ellipsis resolution and scope determination can be captured. As a consequence, an account of the problematic examples follows directly from the equational method. The goal of this paper is merely to point out this pleasant aspect of the equational analysis, through its application to these cases. No new analytical methods or associated formalism are presented, with the exception of a straightforward extension of the equational method to intensional logic.Engineering and Applied Science
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