Alonzo Church (June 14, 1903
– August 11, 1995) was an American mathematician and logician who made major contributions to
mathematical logic and the foundations of theoretical computer science. He is best known
for the
lambda calculus,
Church–Turing thesis,
Frege–Church ontology, and the
Church–Rosser
theorem.
Life
Alonzo
Church was born on June 14, 1903 in Washington, D.C. where his father, Samuel Robbins Church, was the
Justice of the Municipal Court for the District of Columbia.
The family later moved to Virginia after his father lost this
position because of failing eyesight.
With help from his
uncle, also named Alonzo Church, he was able to attend the
Ridgefield School for Boys in Ridgefield, Connecticut. After graduating from Ridgefield in 1920,
Church attended Princeton University where he was an exceptional student, publishing his
first paper, on Lorentz
transformation, and graduating in 1924 with a degree in
mathematics. He stayed on at Princeton, earning a
Ph.D. in mathematics in three years
under
Oswald Veblen.
He married Mary Julia Kuczinski in 1925 and the couple had three
children, Alonzo Church, Jr. (1929), Mary Ann (1933) and Mildred
(1938).
After
receiving his Ph.D. he taught briefly as an instructor at the
University of
Chicago and then received a two-year National Research
Fellowship. This allowed him to attend Harvard
University in 1927–1928 and then both University of
Göttingen and University of Amsterdam the following year. He taught at
Princeton, 1929–1967, and at the University of
California, Los Angeles, 1967–1990. In 1990, he received the Doctor
Honoris Causa from the
State University of New
York at Buffalo in connection with an international symposium
in his honor organized by
John
Corcoran.
He had previously received honorary
doctorates from Case Western Reserve
University (1969) and Princeton University (1985).
He died in
1995 and was buried in Princeton Cemetery.
Mathematical work
Church is best known for the following accomplishments:
The lambda calculus emerged in his famous 1936 paper showing the
existence of an "
undecidable
problem". This result preceded
Alan
Turing's famous work on the
halting
problem, which also demonstrated the existence of a problem
unsolvable by mechanical means. Church and Turing then showed that
the lambda calculus and the
Turing
machine used in Turing's halting problem were equivalent in
capabilities, and subsequently demonstrated a variety of
alternative "mechanical processes for computation." This resulted
in the Church–Turing thesis.
The lambda calculus influenced the design of the
LISP programming language and
functional programming
languages in general. The
Church
encoding is named in his honor.
Students
Church's doctoral students were an extraordinarily accomplished
lot, including
C. Anthony Anderson,
Peter B. Andrews,
George A. Barnard,
William W. Boone,
Martin
Davis,
Alfred L. Foster,
Leon Henkin,
John G. Kemeny,
Stephen C. Kleene,
Simon
B. Kochen,
Maurice L'Abbé,
Isaac
Malitz, Gary Mar,
Michael O.
Rabin,
Nicholas Rescher,
Hartley Rogers, Jr.,
J. Barkley
Rosser,
Dana Scott,
Raymond Smullyan, and
Alan Turing. See
[8012].A more complete list is at
[8013] as part of the
Mathematics Genealogy
Project.
Books
- Alonzo Church, Introduction to Mathematical Logic
(ISBN 978-0691029061)
- Alonzo Church, The Calculi of Lambda-Conversion (ISBN
978-0691083940)
- Alonzo Church, A Bibliography of Symbolic Logic,
1666–1935 (ISBN 978-0821800843)
- C. Anthony Anderson and Michael Zelëny, editors, Logic,
Meaning and Computation: Essays in Memory of Alonzo Church
(ISBN 978-1402001413)
See also
Footnotes
Sources
- Enderton, Herbert B., Alonzo
Church: Life and Work. Introduction to the Collected Works
of Alonzo Church, MIT Press, not yet published.
- Enderton, Herbert B., In memoriam: Alonzo Church, The Bulletin of
Symbolic Logic, vol. 1, no. 4 (Dec. 1995), pp. 486–488.
- Wade, Nicholas, Alonzo Church, 92, Theorist of the Limits of
Mathematics (obituary), The New York Times, September
5, 1995, p. B6.
- Hodges, Wilfred, Obituary: Alonzo Church, The Independent
(London), September 14, 1995.
- Alonzo Church interviewed by William Aspray on
17 May 1984. The Princeton Mathematics Community in the 1930s:
An Oral-History Project, transcript number 5.
- Rota, Gian-Carlo, Fine Hall in its golden age: Remembrances of Princeton in
the early fifties. In A Century of Mathematics in America,
Part II, edited by Peter Duren, AMS History of Mathematics,
vol 2, American Mathematical Society, 1989, pp. 223–226. Also
available here.
External links