Georg Gottlob

Linear time datalog and branching time logic

We survey recent results about the relation between Datalog and temporal verification logics. Datalog is a well-known database query language relying on the logic programming paradigm. We introduce Datalog LITE, a fragment of Datalog with Well-founded negation, which has an easy stratified semantics and a linear time model checking algorithm. Datalog LITE subsumes temporal languages such as CTL and the alternation-free u-calculus. We give easy syntactic characterizations of these temporal languages by fragments of Datalog LITE, and show that Datalog LITE has the same expressive power as the alternation-free portion of guarded fixed point logic.