Propositional Logic for Knowledge Representation and Formalization of Reasoning

The purpose of this master thesis is to investigate the basic concepts of propositional logic for knowledge representation and formalization of reasoning in Artificial Intelligence. The different properties of logical propositions are discussed. The basic and derived logical connectives are used to establish the compound statements, and the truth tables are constructed to investigate the properties of logical connectives. Such propositions as tautology, satisfiability, contradiction, contingency, logical entailment and logical equivalence are analyzed. Three algebraic normal forms - negation normal form, disjunctive normal form and conjunctive normal form are studied. Horn clauses are implemented. Two forms of valid inferences as modus ponens and modus tollens are considered. Some examples are provided to better understand the main properties of propositional logic. Keywords: Propositional Logic, Logical Connectives, Normal Forms, Horn Clauses, Modus Ponens, Modus Tollens