Games and Total DatalogNeg Queries

Jörg Flum, Max Kubierschky, Bertram Ludäscher
Abstract. We show that the expressive power of DatalogNeg programs under the well-founded semantics does not decrease when restricted to total programs thereby affirmatively answering an open question posed by Abiteboul, Hull, and Vianu [AHV95]. In particular, we show that for every such program there exists an equivalent total program whose only recursive rule is of the form where move is definable by a quantifier-free first-order formula. Also for the noninflationary semantics we derive a new normal form whose only recursive rule simulates a version of the game of life.