Through stone duality. What about them in particular?
Trivially, a co-X in C^op is the same but flipped as an X in C.
Then as you know, Stone duality says that CABA = Set^op.
So a co-X in CABA is the same but flipped as an X in Set.
(I think it works constructively too if one replaces Boolean with Heyting?)
Through stone duality. What about them in particular?
Trivially, a co-X in C^op is the same but flipped as an X in C.
Then as you know, Stone duality says that CABA = Set^op.
So a co-X in CABA is the same but flipped as an X in Set.
(I think it works constructively too if one replaces Boolean with Heyting?)