Text Understanding in LILOG

The IBM project LILOG presented in this volume represents afundamental stepbeyond computer science as hithertounderstood. It was a successful project in every respect andhas shed light on conjectured basic interrelations betweenknowledge processing and language definition. Knowledgeprocessing is strongly coupled to the natural language usedand for applied knowledge processing an information base isneededwhich defines the semantic contents andinterrelations of the language.The LILOG project was an implementation of an informationbasein the German language. A set of tools was alsodeveloped to work with the system, including structuredman-machine interfaces using natural language, inferencealgorithms, and a complete subsystem to acquire and storethe required knowledge.The LILOG project started in 1985 and a functional systemwas demonstrated in 1991. The project involved approximately200 of the scientists working in Germany in the fields ofcomputational linguistics, natural language understandingsystems, and artificial intelligence. The project provesthat a cooperative project between universities and industrycan produce useful results both in pure research and inimplemented methods and tools.

The IBM project LILOG is presented in this book. The project started in 1985 and led in 1991 to a functional knowledge base with a natural language user interface. The project involved 200 scientists from universities and industry.

Introducing LILOG.- Text understanding - The challenges to come.- A formalism for natural language - STUF.- The language of STUF.- Chart-parsing of STUF grammars.- The STUF workbench.- Unification-ID/LP grammars: Formalization and parsing.- A flexible parser for a Linguistic Development Environment.- Gap-Handling mechanisms in categorial grammars.- Outlines of the LEU/2 lexicology.- Morphological processing in the two-level paradigm.- Representing word meanings.- Sortal information in lexical concepts.- Incremental vocabulary extensions in text understanding systems.- Managing lexical knowledge in LEU/2.- The grammars of LILOG.- An alternative phrase structure account of symmetric coordination.- Verb order and head movement.- The Bermuda Triangle: Natural language semantics between linguistics, knowledge representation, and knowledge processing.- Presupposition, anaphora, and lexical content.- Anaphora and domain restriction.- On representing the temporal structure of texts.- The treatment of plurality in L LILOG.- The knowledge representation language LLILOG.- Knowledge packets and knowledge packet structures.- Deductive aspects of three-valued logic.- The LILOG inference engine.- Knowledge based control of the LILOG inference engine: Kinds of metaknowledge.- Attributive description formalisms ... and the rest of the world.- The background knowledge of the LILOG system.- The LILOG ontology from a linguistic point of view.- A knowledge engineering environment for LILOG.- Knowledge engineering in the context of related fields of research.- LILOG-DB: Database support for knowledge based systems.- Processing of spatial expressions in LILOG.- Phenomena of localization.- Verbs of motion and position: On the optionality of the local argument.- Why a hill can't be avalley: Representing gestalt and position properties of objects with object schemata.- Object-oriented representation of depictions on the basis of cell matrices.- Integrating a generation component into a natural language understanding system.- From knowledge structures to text structures.- The formulator.- Constructing a context for LEU/2.- The text understanding system LEU/2.- The trace of building a large AI system.