Shyshatska O. Formal database models and multi-valued logic

The dissertation is devoted to the study of multivalued logics of formal database models and the construction of new program-oriented logics. Their distinctive feature is the use of special truth values that indicate uncertainty, errors, etc. Such logics naturally appear for software systems which work with various types of uncertainties and errors. For the first time a new class of software-oriented logical formalisms was proposed and investigated. The propositional five-valued logic and logic of five-valued quasiary predicates are these formalisms. The basis of the study is the compositional-nominative approach. This approach is common to logic and programming. Algebras of five-valued functions and predicates are constructed. The semantic properties of such algebras and the corresponding five-valued logic are described.