Which of these mathematicians was born at an earlier date, Georg Cantor or Grigory Margulis?
Georg Cantor Georg Ferdinand Ludwig Philipp Cantor ( ; ] ; March 3 [O.S. February 19] 1845  – January 6, 1918) was a German mathematician. He invented set theory, which has become a fundamental theory in mathematics. Cantor established the importance of one-to-one correspondence between the members of two sets, defined infinite and well-ordered sets, and proved that the real numbers are more numerous than the natural numbers. In fact, Cantor's method of proof of this theorem implies the existence of an "infinity of infinities". He defined the cardinal and ordinal numbers and their arithmetic. Cantor's work is of great philosophical interest, a fact of which he was well aware.
Feliks Barański Feliks Barański (1915-2006) was a Polish mathematician and an active member of the so-called Lwów School of Mathematics. Born May 1915 in Lwów, Austria-Hungary (modern Lviv, Ukraine), he joined the circle of young, talented mathematicians formed around Stefan Banach and Hugo Steinhaus. During the period of German occupation of his hometown he made his living as a lice feeder in the institute of Rudolf Weigl. Expelled from Lwow after the war, he settled in Kraków, where he joined the local Kraków University of Technology. He was also admitted into the Polish Mathematics Society.