Piotr Kulicki

We investigate a specic model of knowledge and beliefs and their dynamics. The model is inspired by public announcement logic and the approach to puzzles concerning knowledge using that logic. In the model epistemic considerations are based on ontology. The main notion that constitutes a bridge between these two disciplines is the notion of epistemic capacities. Within the model we study scenarios in which agents can receive false announcements and can have incomplete or improper views about other agent's epistemic capacities. Moreover, we try to express the description of problem specication using the tools from applied ontology { RDF format for information and the Protege editor.

In the article attention is paid to the analogy between considerations concerning the number of objects that are the empirical basis for the theory of being and investigations concerning the size of the models necessary for solving formulas on the ground of calculus of names without quantifiers. In both cases a minimum of two objects appear as an answer to the question that has been posed. In explaining the noticed similarity the meaning aspect, as different from the referential aspect of cognition of reality, is pointed to.

A calculus of names is a logical theory describing relations between names. By a pure calculus of names we mean a quantifier-free formulation of such a theory, based on classical propositional calculus. An axiomatisation of a pure calculus of names is presented and its completeness is discussed. It is shown that the axiomatisation is complete in three different ways: with respect to a set theoretical model, with respect to Leśniewski's Ontology and in a sense defined with the use of axiomatic rejection. The independence of axioms is proved. A decision procedure based on syntactic transformations and models defined in the domain of only two members is defined