John Barkley Rosser Sr., American logician (d. 1989)
John Barkley Rosser Sr. (December 6, 1907 – September 5, 1989) was an American logician, a student of Alonzo Church, and known for his part in the Church–Rosser theorem, in lambda calculus. He also developed what is now called the "Rosser sieve", in number theory. He was later director of the Army Mathematics Research Center at the University of Wisconsin–Madison. Rosser also authored mathematical textbooks.
In 1936, he proved Rosser's trick, a stronger version of Gödel's first incompleteness theorem, showing that the requirement for ω-consistency may be weakened to consistency. Rather than using the liar paradox sentence equivalent to "I am not provable," he used a sentence that stated "For every proof of me, there is a shorter proof of my negation".
In prime number theory, he proved Rosser's theorem.
The Kleene–Rosser paradox showed that the original lambda calculus was inconsistent.
Rosser died of an aneurysm September 5, 1989, at his home in Madison, Wisconsin.Rosser's son, John Barkley Rosser Jr., is a mathematical economist and professor at James Madison University in Harrisonburg, Virginia.
1907Dec, 6
John Barkley Rosser Sr.
Choose Another Date
Events on 1907
- 23May
Parliament of Finland
The unicameral Parliament of Finland gathers for its first plenary session. - 22Jun
Charing Cross, Euston and Hampstead Railway
The London Underground's Charing Cross, Euston and Hampstead Railway opens. - 7Sep
RMS Lusitania
Cunard Line's RMS Lusitania sets sail on her maiden voyage from Liverpool, England, to New York City. - 16Nov
RMS Mauretania (1906)
Cunard Line's RMS Mauretania, sister ship of RMS Lusitania, sets sail on her maiden voyage from Liverpool, England, to New York City. - 31Dec
Times Square
The first New Year's Eve celebration is held in Times Square (then known as Longacre Square) in Manhattan.