Computability Learning Seminar

Michael Deveau, Department of Pure Mathematics, University of Waterloo

"Isomorphisms that cannot be coded by computable relations"

When we wish to show that two structures have an isomorphism of a certain degree between them, a standard technique is to carefully choose some computable set $U$ and then show that under a natural isomorphism $f$, the image $f(U)$ has the degree we are interested in. We show a case of two structures isomorphic to $(\omega, <)$ where this method of establishing the degree of the isomorphism between them will not work.

MC 5413