Stanisław Jaśkowski

Stanisław Jaskowski ( born April 22, 1906 in Warsaw, † November 16, 1965 ) was a Polish logician of Lvov -Warsaw School. He contributed significantly to the development of systems of natural deduction proof theory and formal semantics. Jaskowski studied mathematics with Jan Łukasiewicz. He participated in the defense of Warsaw in 1939 as a volunteer. In 1946 he became a professor at the University of Thorn and 1959 its rector.