Originally published as preprint, January 1978.
MSC 2000: 18A32,18B25,18C15,18D05,18D35
Keywords: internal category, 2-category, effective profunctorial monad, 2-topos
Republished in:
Reprints in Theory and Applications of Categories,
No. 19 (2010) pp. 1-38
http://www.tac.mta.ca/tac/reprints/articles/19/tr19.dvi
http://www.tac.mta.ca/tac/reprints/articles/19/tr19.ps
http://www.tac.mta.ca/tac/reprints/articles/19/tr19.pdf