A Query Language for Extended Semantic Networks

This paper describes a query language for extended semantic networks proposed by Igor’ Petrovich Kuznetsov in the second half of the 1980s. The formalism itself has been developed and applied for more than three decades by the team in the Laboratory of Computational Linguistics at the Institute of Informatics Problems of the Russian Academy of Sciences. The DEKL language for operation with extended semantic networks is well known. The relations in such networks are characterized in the general case by different arities and, for this reason, are described by tuples, in which a relation precedes all its arguments and there are two additional elements, such as a c-vertex and a p-vertex. In this paper, an attempt is made to create a query language for extended semantic networks that would be similar in essence to structured query languages and designed for use by contemporary software tools. The basic types of queries with examples are presented, the problem of imposing constraints is formulated, and a set of algorithms solving this problem and underlying the query language interpreter is given.