A Deductive Question Answering System on Relational Data Bases

Abstract

This paper describes a new formalization of a deductive question answering system on a relational data base using a theorem proving technique. A theorem proving procedure for a finite domain is investigated and a direct proof procedure based on substitutions of equivalent formulas which employs the breadth first search is intorudced . The search strategy is then expanded to set operations of the relational algebra which are incorporated into the proof procedure in order to increase the data base search efficiency. Virtual relations are realized by means of introducing several axioms and utilizing the deductive capability of the logical system . Furthermore, a conditional domain is introduced as one of the virtual domains and is used to give a relational view to a pseudo relational data base which can represent exceptional cases using some link information . A query transformation system called DBAP (Data Base Access Planner) which embodies those features is implemented in QLISP .