Efficient Support for Mode-Directed Tabling in the YapTab Tabling System

Mode-directed tabling is an extension to the tabling technique that supports the definition of mode operators for specifying how answers are inserted into the table space. In this paper, we focus our discussion on the efficient support for mode directed-tabling in the YapTab tabling system. We discuss 7 different mode operators and explain how we have extended and optimized YapTab's table space organization to support them. Initial experimental results show that our implementation compares favorably with the B-Prolog and XSB state-of-the-art Prolog tabling systems.