An approach for bringing semantic, as well as syntactic, information to bear on the problem of theorem-proving search for Question-Answering (QA) Systems is descrilsed. The approach is embodied in a search algorithm, the Q* search algorithm, developed to control deductive searches in an experimental system. The Q* algorithm is part of a system, termed the Maryland Refutation Proof Procedure System (MRPPS), which incorporates both the Q* algorithm, which performs the search required to answer a query, and an inferential component, which performs the logical manipulations necessary to deduce a clause from one or two other clauses. The inferential component includes many refinements of resolution.#R##N##R##N#The Q* algorithm generates nodes in the search space, applying semantic and syntactic information to direct the search. The use of semantics permits paths to be terminated and fruitful paths to be explored. The paper is restricted to a description of the use of syntactic and semantic information in the Q* algorithm.
['Jack Minker', 'Daniel H. Fishman', 'James R. McSkimin']
The Q* algorithm: a search strategy for a deductive question-answering system