Deductive Querying of Natural Logic Bases

Abstract

We introduce a dedicated form of natural logic intended for representation of sentences in a knowledge base. Natural logic is a version of formal logic whose sentences cover a stylized fragment of natural language. Thus, the sentences in the knowledge base can be read and understood directly by a domain expert, unlike, say, predicate logic and description logic. The paper describes the inference rules enabling deductive querying of the knowledge base. The natural logic sentences and the inference rules are represented in Datalog providing a convenient graph form. As such, the natural logic knowledge base may be viewed as an enriched formal ontology structure. We describe various query facilities including pathway finding accommodated by this setup.