Computability Learning Seminar

Beining Mu, University of Waterloo

Thickness Lemma and Infinite Injury Priority Argument

In this talk, I will present Strong Thickness Lemma, which states that every piecewise computable c.e. set has a thick subset which lies outside of an upper cone of a non-computable c.e. set, as an example of infinite injury priority argument. In addition, I will discuss how thickness lemma implies the lack of least upper bound for infinite ascending c.e. degrees.

MC 5403