Grammatical Concept Representation for Randomised Optimisation Algorithms in Relational Learning

This paper proposes a novel grammar-based framework of concept representation for randomized search in Relational Learning (RL), namely for Inductive Logic Programming. The utilization of grammars guarantees that the search operations produce syntactically correct concepts and that the background knowledge encoded in the grammar can be used both for directing the search and for restricting the space of possible concepts to relevant candidate concepts (semantically valid concepts). Not only that it enables handling and incorporating the domain knowledge in a declarative fashion, but grammars also make the new approach transparent, flexible, less problem-specific and allow it to be easily used by almost any randomized algorithm within RL. Initial test results suggest that the grammar-based algorithm has strong potential for RL tasks.