Wadge degrees of omega-languages of deterministic Turing machines
We describe Wadge degrees of omega-languages recognizable by deterministic Turing machines. In particular, it is shown that the ordinal corresponding to these degrees is xi(omega) where xi = omega(1)(CK) is the first non-recursive ordinal known as the Church-Kleene ordinal. This answers a question raised in [2].
wadge degree omega-language turing machine ordinal hierarchy set-theoretic operation