Hostname: page-component-74656f9884-npj9w Total loading time: 0 Render date: 2026-11-09T19:05:48.259Z Has data issue: false hasContentIssue false

Computability and Recursion

Published online by Cambridge University Press:  15 January 2014

Robert I. Soare*
Affiliation:
Department of Mathematics, University of Chicago, Chicago, Illinois 60637-1546, USA E-mail: soare@math.uchicago.edu, http://www.cs.uchicago.edu/~soare, Papers posted at, ftp:cs.uchicago.edu/ftp/pub/users/soare

Abstract

We consider the informal concept of “computability” or “effective calculability” and two of the formalisms commonly used to define it, “(Turing) computability” and “(general) recursiveness”. We consider their origin, exact technical definition, concepts, history, general English meanings, how they became fixed in their present roles, how they were first and are now used, their impact on nonspecialists, how their use will affect the future content of the subject of computability theory, and its connection to other related areas.

After a careful historical and conceptual analysis of computability and recursion we make several recommendations in section §7 about preserving the intensional differences between the concepts of “computability” and “recursion.” Specifically we recommend that: the term “recursive” should no longer carry the additional meaning of “computable” or “decidable;” functions defined using Turing machines, register machines, or their variants should be called “computable” rather than “recursive;” we should distinguish the intensional difference between Church's Thesis and Turing's Thesis, and use the latter particularly in dealing with mechanistic questions; the name of the subject should be “Computability Theory” or simply Computability rather than “Recursive Function Theory.”

Information

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable