%0 Journal Article
%T Ambiguity of ¦Ø-Languages of Turing Machines
%A Olivier Finkel
%J Mathematics
%D 2012
%I arXiv
%R 10.2168/LMCS-10(3:12)2014
%X An {\omega}-language is a set of infinite words over a finite alphabet X. We consider the class of recursive {\omega}-languages, i.e. the class of {\omega}-languages accepted by Turing machines with a B\"uchi acceptance condition, which is also the class {\Sigma}11 of (effective) analytic subsets of X{\omega} for some finite alphabet X. We investigate here the notion of ambiguity for recursive {\omega}-languages with regard to acceptance by B\"uchi Turing machines. We first present in detail essentials on the literature on {\omega}-languages accepted by Turing Machines. Then we give a complete and broad view on the notion of ambiguity and unambiguity of B\"uchi Turing machines and of the {\omega}-languages they accept. To obtain our new results, we make use of results and methods of effective descriptive set theory.
%U http://arxiv.org/abs/1209.5669v3