Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-05T13:47:43.728Z Has data issue: false hasContentIssue false
  • English
  • Français

Recursive Unsolvability of a problem of Thue

Published online by Cambridge University Press:  12 March 2014

Emil L. Post
Emil L. Post*
Affiliation:
The City College, College of The City of New York
Get access Rights & Permissions [Opens in a new window]

Extract

Alonzo Church suggested to the writer that a certain problem of Thue [6] might be proved unsolvable by the methods of [5]. We proceed to prove the problem recursively unsolvable, that is, unsolvable in the sense of Church [1], but by a method meeting the special needs of the problem.

Thue's (general) problem is the following. Given a finite set of symbols α1, α2, …, αμ, we consider arbitrary strings (Zeichenreihen) on those symbols, that is, rows of symbols each of which is in the given set. Null strings are included.

Type
Research Article
Information
The Journal of Symbolic Logic , Volume 12 , Issue 1 , March 1947 , pp. 1 - 11
Copyright
Copyright © Association for Symbolic Logic 1947

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.)

References

[1]Church, Alonzo, An unsolvable problem of elementary number theory, American journal of mathematics, vol. 58 (1936), pp. 345–363.CrossRefGoogle Scholar
[2]Post, Emil L., Finite combinatory processes—formulation 1, this Journal, vol. 1 (1936), pp. 103–105.Google Scholar
[3]Post, Emil L., Formal reductions of the general combinatorial decision problem, American journal of mathematics, vol. 65 (1943), pp. 197–215.CrossRefGoogle Scholar
[4]Post, Emil L., Recursively enumerable sets of positive integers and their decision problems, Bulletin of the American Mathematical Society, vol. 50 (1944), pp. 284–316.CrossRefGoogle Scholar
[5]Post, Emil L., A variant of a recursively unsolvable problem, Bulletin of the American Mathematical Society, vol. 52 (1946), pp. 264–268.CrossRefGoogle Scholar
[6]Thue, Axel, Probleme über Veränderungen von Zeichenreihen nach gegebenen Regeln, Skrifter utgit av Videnskapsselskapet i Kristiania, I. Matematisk-naturvidenskabelig Klasse 1914, no. 10 (1914), 34 pp.Google Scholar
[7]Turing, A. M., On computable numbers, with an application to the Entscheidungsproblem, Proceedings of the London Mathematical Society, ser. 2 vol. 42 (1937), pp. 230–265.CrossRefGoogle Scholar
[8]Turing, A. M., Computability and λ-definability, this Journal, vol. 2 (1937), pp. 153–163.Google Scholar