Stanisław Leśniewski

Stanisław Leśniewski (; 30 March 1886 – 13 May 1939) was a Polish mathematician, philosopher and logician. A professor of mathematics at the University of Warsaw, he was a leading representative of the Lwów–Warsaw School of Logic and is known for coining and introducing the concept of mereology as part of a comprehensive framework for logic and mathematics. Provided by Wikipedia