Relaxing underspecified semantic representations for reinterpretation (Q5931129)

This article investigates the foundations of underspecified reinterpretation of Natural Language (NL) semantic representations, and its basic operation of relaxation, in the framework of Constraint Language for Lambda Structures (CLLS), a formalism devoted to NL, semantic underspecification. In CLLS, the underspecified semantic representations are expressed by tree descriptions subsuming dominance constraints. Section 2 of the paper introduces tree descriptions in CLLS formalism. Section 3 discusses the underspecification approach to reinterpretation and specifies the overgeneration problem. Section 4 is devoted to the formalization of the notion of relaxation, what means a relaxation to be safe (the overgeneration problem is avoided), and to be open (arbitrary material can be filled into the gap). Section 5 develops techniques for reasoning about the structural properties of tree descriptions in CLLS; fragments and chains of fragments are defined, and some useful properties of these objects are proved. Section 6 presents a prototypical toy grammar for deriving relaxed underspecified representations. The final Section 7 shows that every relaxed description produced by the syntax/semantics interface of the proposed toy grammar is open and safe. These proof techniques may be extended to more detailed NL formal grammars.