23 Aug
2002
23 Aug
'02
2:28 p.m.
Galchin Vasili wrote:
Dear CT Community,
I am new to Topos theory. Is it true that Hom[1->omega] in a topos defines a Heyting algebra? If so, please give me a reference where this is proved.
Thanks and regards, Bill Halchin
You will find this in MacLane and Moerdijk, Sheaves in Geometry and Logic. Check the index for "heyting algebras: of subobjects". I have the first printing of the first edition in which this result is Proposition 1 of the 8th section of chapter III. I believe this result can also be found in Lambek and Scott as well as Borceaux. Hope this helps. Bob McGrail Assistant Professor of Computer Science Bard College Annandale-on-Hudson, NY 12504 23-Aug-2002 16:27:21 -0300,935;000000000000-00000000