Reversible delayed lexical choice in a bidirectional framework

We describe a bidirectional framework for natural language parsing and generation, using a typedfeatureformalismand an HPSG-based grammar with a parser and generator derived from parallel processing algorithms. We present an approach to delayed lexical choice in generation, based on subsumption within the sort hierarchy, using a lexicon of underinstantiatedsigns which are derived from the normal lexicon by lexical rules. We then show how delayed lexical choice can be used in parsing, so that some types of ill-formed inputs can be parsed, but wellformed outputs are generated, using the same shared linguistic information. 1 A bidirectional framework In our bidirectional framework for a natural language engine, the linguistic descriptions in the grammar and lexicon are shared resources which are used, in appropriately compiled forms, for both parsing and generation. Like the Core Language Engine (CLE) (Alshawi, 1992), we use a uni cation-based phrase structure grammar, a logical form rep...

• Type: Conference
• Year: 1996
• Where: COLING
• Authors: Graham Wilcock, Yuji Matsumoto
• Keywords: Bidirectional Framework, COLING 1996, COLING 2008, Delayed Lexical Choice, Natural Language