Andrzej Grzegorczyk
Andrzej Grzegorczyk ([ˈandʐɛj ɡʐɛˈɡɔrt͡ʂɨk]; 22 August 1922 – 20 March 2014) was a Polish logician, mathematician, philosopher and ethicist. He was noted for his work in computability, mathematical logic and the foundations of mathematics.