A Constraint Database System for Temporal Knowledge

This paper describes how the technology of deductive constraint database systems and constraint query languages can be used to represent and reason with tem poral knowledge First we summarize our approach to manipulating constraints over reals within deductive database sys tems This approach is based on the compile time rewriting of clauses which are not admissible Then we show how the timestamping of facts and rules in temporal databases can be mapped to constraints over reals Subsequently we present a more e cient and elegant ap proach which is based on a special tem poral constraint solver