Burkhard Freitag

AMOS: A Natural Language Parser Implemented as a Deductive Database in LOLA

In this paper we present the set-oriented bottom-up parsing system AMOS which is a major application of the LOLA deductive database system. AMOS supports the morpho-syntactical analysis of Old Hebrew and has now been operationally used by linguists for a couple of years. The system allows the declarative specification of Definite Clause Grammar rules. Due to the set-oriented bottom-up evaluation strategy of LOLA LOLA it is particularly well suited to the analysis of language ambiguities.

LOLA — ein deduktives Datenbanksystem

Die Logiksprache LOLA ist als Anfragesprache fur ein deduktives Datenbanksystem entwickelt worden. LOLA hat eine deklarative Semantik und integriert Deduktion mit effizientem Datenzugriff durch die Anwendung relationaler Techniken. Die Sprache LOLA wird in dem in diesem Artikel vorgestellten experimentellen deduktiven Datenbanksystem verwendet, das ebenfalls den Namen LOLA tragt. Es bietet als zusatzliche Eigenschaften die Verwendung von Funktionen der Hostsprache Lisp und einen automatischen Zugriff auf externe relationale Datenbanken. LOLA ist in CommonLisp implementiert und lauft zur Zeit auf SUN Workstations.

Transactions and Change in Logic Databases

During the last years, a number of formal speciication languages for knowledge-based systems have been developed. Characteristic for knowledge-based systems are a complex knowledge base and an inference engine which uses this knowledge to solve a given problem. Speciication languages for knowledge-based systems have to cover both aspects: they have to provide means to specify a complex and large amount of knowledge and they have to provide means to specify the dynamic reasoning behaviour of a knowledge-based system. This paper will focus on the second aspect, which is an issue considered to be unsolved. For this purpose, we have surveyed existing approaches in related areas of research. We have taken approaches for the speciication of information systems (i.e., Language for Conceptual Modelling and Troll), approaches for the speciication of database updates and the dynamics of logic programs (Transaction Logic and Dynamic Database Logic), and the approach of Abstract State Machines.