Jonathon Funk

The Universal Covering of an Inverse Semigroup

Benjamin Steinberg, Jonathon Funk, J. Funk, 2010, Appl. Categorical Struct..

Toposes for semigroups: an invitation

Pieter Hofstra, Jonathon Funk, 2021, Semigroup Forum.

Singular Coverings of Toposes

Jonathon Funk, Marta Bunge, 2006 .

ISOTROPY AND CROSSED TOPOSES

Benjamin Steinberg, Pieter Hofstra, Jonathon Funk, 2012 .