Abstract
A Grothendieck topos has the property that its Yoneda embedding has a left-exact left adjoint. A category with the latter property is called lex-total. It is proved here that every lex-total category is equivalent to its category of canonical sheaves. An unpublished proof due to Peter Freyd is extended slightly to yield that a lex-total category, which has a set of objects of cardinality at most that of the universe such that each object in the category is a quotient of an object from that set, is necessarily a Grothendieck topos.
Original language | English |
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Pages (from-to) | 199-208 |
Number of pages | 10 |
Journal | Bulletin of the Australian Mathematical Society |
Volume | 23 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1981 |