LP with Flexible Grouping and Aggregates Using Modes

We propose a new grouping operator for logic programs based on the group_by operator of SQL. The novelty of our proposal lies in the use of modes, which allows us to relax some rather unpractical constraints on variable occurrences while retaining a straightforward semantics. Moreover, modes allow us to prove properties regarding groundness of computed answer substitutions and termination. The resulting class of programs enjoys a simple and intuitive semantics.

• Type: Conference
• Year: 2009
• Where: LOPSTR
• Authors: Marcin Czenko, Sandro Etalle
• Keywords: Artificial Intelligence, Computed Answer Substitutions, Group_by Operator, LOPSTR 2009, Straightforward Semantics