Computability Learning Seminar

Mohammad Mahmoud, Department of Pure Mathematics, University of Waterloo

“The Turing Ordinal”

We present the notion of Turing Ordinal of a class of structures. The Turing Ordinal was introduced by Jockusch and Soare as a computability theoretic method for comparing complexities of classes of structures. We explain an example by Montalban of a class of structures that doesn’t have a Turing Ordinal.

M3-4206