Complex sentence: John Hamal Hubbard (born October 6 or 7,1945; the actual date is unknown) is an American mathematician and professor at Cornell University and the Université de Provence.
Split into simpler sentences: John Hamal Hubbard was born on October 6 or 7,1945 (the actual date is unknown). He is an American mathematician who is currently a professor at Cornell University and the Université de Provence.