Towards Learning Stochastic Logic Programs from Proof-Banks

Abstract

Stochastic logic programs combine ideas from probabilistic grammars with the expressive power of definite clause logic; as such they can be considered as an extension of probabilistic context-free grammars. Motivated by an analogy with learning tree-bank grammars, we study how to learn stochastic logic programs from proof-trees. Using proof-trees as examples imposes strong logical constraints on the structure of the target stochastic logic program. These constraints can be integrated in the least general generalization (lgg) operator, which is employed to traverse the search space. Our implementation employs a greedy search guided by the maximum likelihood principle and failure-adjusted maximization. We also report on a number of simple experiments that show the promise of the approach.