Implementing a Japanese Semantic Parser Based on Glue Approach

Implementing a Japanese Semantic Parser Based on Glue Approach Hiroshi Umemoto Fuji Xerox Co., Ltd. 430 Sakai, Nakaimachi, Ashigarakami-gun, Kanagawa 259-0157, Japan, Hiroshi.Umemoto@fujixerox.co.jp Abstract. This paper describes the implementation of a Japanese semantic parser based on glue ap- proach. The parser is designed as domain-independent, and produces fully scoped higher-order in- tensional logical expressions, coping with semantically ambiguous sentences without storage mechanism. It is constructed from an English semantic parser on top of Lexical-Functional Gram- mar (LFG), and it attains broad coverage through relatively little construction effort, thanks to the parallelism of the LFG grammars. I outline the parser, and I present the analyses of Japanese idio- syncratic expressions including floated numerical quantifiers, showing the distinct readings of dis- tributive and cumulative, as well as a double-subject construction and focus particles. I also explain the analyses of expressions that are syntactically parallel but semantically distinct, such as relative tense in subordinate clauses. Keywords: formal semantics, syntax-semantics interface, linear logic, semantic composition 1 Introduction The glue approach to semantic interpretation (glue semantics) provides the syntax-semantics interface where its semantic composition is represented as a linear logic derivation [1, 2]. Glue semantics realizes semantic ambiguity with multiple proofs from the same set of premises corresponding to syntactic items in a sentence, and then it requires no special machineries such as storages. Employing linear logic, it guarantees the semantic completeness and coherence of its results. In other words, all of the require- ments of the premises are satisfied and no unused premises remain in linear logic derivations. In addi- tion, glue semantics is not restricted to any specific formalism although it was primarily developed for Lexical-Functional Grammar (LFG), and it can be used with both various syntactic formalisms and meaning representations [3]. I will present the implementation of a Japanese semantic parser based on glue approach. The imple- mentation of glue semantics for English was constructed and incorporated into real-world application systems [4, 5]. However, the theory has not been applied to other languages than English in broad cov- erage. The Japanese parser is constructed in the same framework as the English parser. Both parsers are designed as domain-dependent, and they produce fully scoped higher-order intensional logical expres- sions of the kind familiar to traditional formal semanticists as the meanings of sentences. The Japanese parser, as well as the English counterpart, aims to cover wide-ranging real texts, and is built on top of an industrial broad-coverage Japanese grammar based on LFG [6]. The Japanese grammar has been devel- oped through the Parallel Grammar (ParGram) project. The ParGram project uses the Xerox Linguistic Environment (XLE), an efficient parser and grammar development platform based on LFG, and aims to test the formalism for its universality and coverage limitations and see how far parallelism can be main- tained across languages [7]. 2 Outline of the Parser The interpretation of glue semantics is comprised of two phases. The first phase is to give rise to mean- ing constructors, each of which consists of a meaning term and …

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