Complex sentence: Nachman Aronszajn (1907-1980), was a Polish American mathematician of Jewish descent, who received his Ph.D. from the University of Warsaw, in 1930, in Poland.
Split into simpler sentences: Nachman Aronszajn (1907-1980), was a Polish American mathematician of Jewish descent. He received his Ph.D. from the University of Warsaw, in 1930, in Poland.