Random reals à la Chaitin with or without prefix-freeness

We give a general theorem that provides examples of n-random reals à la Chaitin, for every n ≥ 1; these are halting probabilities of partial computable functions that are universal by adjunction for the class of all partial computable functions, The same result holds for the class functions of parti...

Descripción completa

Detalles Bibliográficos
Autores: Becher, V., Grigorieff, S.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2007
País:Argentina
Institución:Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
Repositorio:Biblioteca Digital (UBA-FCEN)
Idioma:inglés
OAI Identifier:paperaa:paper_03043975_v385_n1-3_p193_Becher
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_03043975_v385_n1-3_p193_Becher
Access Level:acceso abierto
Palabra clave:Algorithmic randomness
Kolmogorov complexity
Omega numbers
Random reals
Function evaluation
Probability
Problem solving
Theorem proving
Descripción
Sumario:We give a general theorem that provides examples of n-random reals à la Chaitin, for every n ≥ 1; these are halting probabilities of partial computable functions that are universal by adjunction for the class of all partial computable functions, The same result holds for the class functions of partial computable functions with prefix-free domain. Thus, the usual technical requirement of prefix-freeness on domains is an option which we show to be non-critical when dealing with universality by adjunction. We also prove that the condition of universality by adjunction (which, though particular, is a very natural case of optimality) is essential in our theorem. © 2007 Elsevier Ltd. All rights reserved.