Solomon Feferman, American philosopher and mathematician (died 2016)

Solomon Feferman was an American philosopher and mathematician who worked in mathematical logic. In addition to his prolific technical work in proof theory, computability theory, and set theory, he was known for his contributions to the history of logic and as a vocal proponent of the philosophy of mathematics known as predicativism, notably from an anti-platonist stance.

December 13 is the 347th day of the year in the Gregorian calendar; 18 days remain until the end of the year.