Axioms for the category of sets and relations

Andre Kornell

We provide axioms for the dagger category of sets and relations that recall recent axioms for the dagger category of Hilbert spaces and bounded operators.

Keywords: relation, dagger category, monoidal category, complete monoid, Hilbert space

2020 MSC: 18M40, 18B05, 18M05

Theory and Applications of Categories, Vol. 44, 2025, No. 10, pp 305-325.

Published 2025-03-20.

http://www.tac.mta.ca/tac/volumes/44/10/44-10.pdf