Alonzo Church

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This article is about the mathematician and logician. For the president of the University of Georgia, U.S.A, see Alonzo S. Church.
Alonzo Church
Alonzo Church.jpg
Alonzo Church (1903–1995)
Born (1903-06-14)June 14, 1903
Washington, D.C., USA
Died August 11, 1995(1995-08-11) (aged 92)
Hudson, Ohio, USA
Residence United States
Nationality American
Fields Mathematics, Logic
Institutions Princeton University 1929–67
UCLA 1967–95
Alma mater Princeton University
Thesis Alternatives to Zermelo's Assumption (1927)
Doctoral advisor Oswald Veblen
Doctoral students C. Anthony Anderson
Peter Andrews
George Alfred Barnard
Martin Davis
Leon Henkin
David Kaplan
John George Kemeny
Stephen Kleene
Gary R. Mar
Michael O. Rabin
Hartley Rogers, Jr
J. Barkley Rosser
Dana Scott
Raymond Smullyan
Alan Turing
Known for Lambda calculus
Church–Turing thesis
Frege–Church ontology
Church–Rosser theorem

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, proving the undecidability of the Entscheidungsproblem, Frege–Church ontology, and the Church–Rosser theorem.

Life[edit]

Alonzo Church was born on June 14, 1903 in Washington, D.C. where his father, Samuel Robbins Church, was the judge 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.[1] After graduating from Ridgefield in 1920, Church attended Princeton University where he was an exceptional student, publishing his first paper, on Lorentz transformations, and graduating in 1924 with a degree in mathematics. He stayed 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 Philosophy and Mathematics at Princeton, 1929–1967, and at the University of California, Los Angeles, 1967–1990. He received honorary Doctor of Science degrees from Case Western Reserve University in 1969,[2] Princeton University in 1985,[3] and the University at Buffalo, The State University of New York in 1990 in connection with an international symposium in his honor organized by John Corcoran.[4]

A deeply religious person, he was a lifelong member of the Presbyterian church.[5]

He died in 1995 and was buried in Princeton Cemetery.

Mathematical work[edit]

Church is best known for the following accomplishments:

The lambda calculus emerged in his 1936 paper showing the unsolvability of the Entscheidungsproblem. This result preceded Alan Turing's 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[edit]

Many of Church's doctoral students have led distinguished careers, including C. Anthony Anderson, Peter B. Andrews, George A. Barnard, David Berlinski, 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 R. Mar, Michael O. Rabin, Nicholas Rescher, Hartley Rogers, Jr., J. Barkley Rosser, Dana Scott, Raymond Smullyan, and Alan Turing.[6] A more complete list of Church's students is available via Mathematics Genealogy Project.

Books[edit]

See also[edit]

Notes[edit]

  1. ^ The Ridgefield School for Boys, also known as the Ridgefield School, was a private school that existed from 1907 to 1938. See The Ridgefield School.
  2. ^ Honorary degrees awarded by Case Western Reserve University
  3. ^ Honorary degrees awarded by Princeton University
  4. ^ Finding Aid for The Honorary Degree Conferral of Doctor of Science to Alonzo Church, 1990
  5. ^ "Introduction Alonzo Church: Life and Work". p. 4. Retrieved 6 June 2012. A deeply religious person, he was a lifelong member of the Presbyterian church. 
  6. ^ "Mathematics Genealogy Project". Archived from the original on 4 August 2010. Retrieved 12 August 2010. 
  7. ^ Henkin, Leon (1957). "Review: Introduction to Mathematical Logic by Alonzo Church". Bull. Amer. Math. Soc. 63 (5): 320–323. doi:10.1090/s0002-9904-1957-10129-3. 
  8. ^ Frink Jr., Orrin (1944). "Review: The Calculi of Lambda-Conversion by Alonzo Church". Bull. Amer. Math. Soc. 50 (3): 169–172. doi:10.1090/s0002-9904-1944-08090-7. 

References[edit]

External links[edit]