A deductive question-answerer for natural language inference

• Published in: Communications of the ACM 1970-03, Vol.13 (3), p.167-183
• Main Authors: Schwarcz, Robert M., Burger, John F., Simmons, Robert F.
• Format: Magazinearticle
• Language: English
• ISSN: 0001-0782; 1557-7317
• DOI: 10.1145/362052.362058

The question-answering aspects of the Protosynthex III prototype language processing system are described and exemplified in detail. The system is written in LISP 1.5 and operates on the Q-32 time-sharing system. The system's data structures and their semantic organization, the deductive question-answering formalism of relational properties and complex-relation-forming operators, and the question-answering procedures which employ these features in their operation are all described and illustrated. Examples of the system's performance and of the limitations of its question-answering capability are presented and discussed. It is shown that the use of semantic information in deductive question answering greatly facilitates the process, and that a top-down procedure which works from question to answer enables effective use to be made of this information. It is concluded that the development of Protosynthex III into a practically useful system to work with large data bases is possible but will require changes in both the data structures and the algorithms used for question answering.