Alfred Tarski (; January 14, 1901 – October 26, 1983) was a Polish logician, mathematician and philosopher. Educated at the University of Warsaw and a member of the Lwów–Warsaw school of logic and the Warsaw school of mathematics and philosophy, he emigrated to the USA in 1939 where he became a naturalized citizen in 1945, and taught and carried out research in mathematics at the University of California, Berkeley from 1942 until his death.