hi @jens-hemelaer, Thx for the references, i take time to study a little.

hi @jens-hemelaer, some news ! For the moment, i'm not sure at all, but : Let $\mathcal{C}$ a category (with a terminal objet $\star$), let $T = \...

Thx !!! It's a very good situation ! Just the kind of example to study the definition ! For me with to deal with $X \mapsto \underline{Hom}(U,X)$ ...

hi @jens-hemelaer, Thank for the comparaison theorem, i will read the Sga 4 version today. For the $\mathbb{F}_2$-story. I extract a more...

Hello @jens-hemelaer, I study the axiom $2=0$. So we have two different topos that classify $\mathbb{F}_2$-algebra. The classical is $\left[ \mathbb...

hi @jens-hemelaer, I'll explain my project to you. (my english is bad !) 1. For the moment learn a little theory by building small example...

And yes, the generic model will be the sheafification of the original generic model. The reason is that geometric morphisms to the subtopos are precis...

I try latex with the symbol dollar. (that ok but the preview doesn't work for me). hum i'm stupid ... thx @jens-hemelaer. I Don't want my axiom a...

Hello, I try to make another baby example. I take the theory of ring with the axiom (it's ok ?) The conversion give : and a cover of a ring R ...

Thank you @jens-hemelaer very much for your calculations which seems to confirm my intuition and the references. It's really nice, the automatic proce...

Hello @elio-pivet, Thx, i thinck, in Olivia's book, you're are mentioning page 88 " quotient and subtopos " ? For the moment, i don't understa...