Abstract

The position of Polish informatics, as well in research as in didactic, has its roots in achievements of Polish mathematicians of Warsaw School and logicians of Lvov-Warsaw School. Jan Lukasiewicz is considered in the world of computer science as the most famous Polish logician. The parenthesis-free notation, invented by him, is known as PN (Polish Notation) and RPN (Reverse Polish Notation). Lukasiewicz created many-valued logic as a separate subject. The idea of multi-valueness is applied to hardware design (many-valued or fuzzy switching, analog computer). Many-valued approach to vague notions and commonsense reasoning is the method of expert systems, databases and knowledge-based systems. Stanis3aw Jaokowski's system of natural deduction is the base of systems of automatic deduction and theorem proving. He created a system of paraconsistent logic. Such logics are used in AI. Kazimierz Ajdukiewicz with his categorial grammar participated in the development of formal grammars, the field significant for programming languages. Andrzej Grzegorczyk had an important contribution to the development of the theory of recursiveness