Hostname: page-component-77f85d65b8-7lfxl Total loading time: 0 Render date: 2026-03-30T00:51:26.981Z Has data issue: false hasContentIssue false

On universal computably enumerable prefix codes

Published online by Cambridge University Press:  01 February 2009

CRISTIAN S. CALUDE
Affiliation:
Department of Computer Science, The University of Auckland, Private Bag 92019, Auckland, New Zealand Email: cristian@cs.auckland.ac.nz
LUDWIG STAIGER
Affiliation:
Martin-Luther-Universität Halle-Wittenberg, Institut für Informatik, D - 06099 Halle, Germany Email: staiger@informatik.uni-halle.de

Abstract

We study computably enumerable (c.e.) prefix codes that are capable of coding all positive integers in an optimal way up to a fixed constant: these codes will be called universal. We prove various characterisations of these codes, including the following one: a c.e. prefix code is universal if and only if it contains the domain of a universal self-delimiting Turing machine. Finally, we study various properties of these codes from the points of view of computability, maximality and density.

Information

Type
Paper
Copyright
Copyright © Cambridge University Press 2009

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