Logical inference in query answering systems based on domain ontologies

This paper describes a proposal of using onto-logical models as a basis of Query Answering Systems design. It is assumed that the models are presented in the form of relations described on some classes of items (ontological concepts) specified by taxonomic trees. There are analyzed the sufficient and necessary conditions for getting the replies to the queries as solution of relational equations based on the data provided by ontological databases. Simple examples illustrate basic concepts of practical realization of the Query Answering Systems based on domain ontologies.