Giorgio Mossa
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 Feb 15 revised Does one need to learn set theory before learning category theory? Added specifications Feb 15 comment Does one need to learn set theory before learning category theory? @MusaAl-hassy indeed you're right. What I meant to say is that it can be useful to have that stuff to understand categorical concepts via example, but of course one could take examples from fields different from topology or geometry (computer science is full of objects where you can get examples). Feb 15 answered The magic of the morphisms Feb 15 answered Does one need to learn set theory before learning category theory? Feb 14 comment How to derive a truth value from the following formula, one where the formula is T and one where it is F @user5647516 I still don't follow, a structure is not something that can be true or false. Feb 14 comment How to derive a truth value from the following formula, one where the formula is T and one where it is F Could you try to be more specific? What do you mean by structure? Because it doesn't seem to be the classical notion of structure. Feb 10 revised Explain “homotopy” to me Fixed grammar Feb 10 comment Explain “homotopy” to me Feel free to ask if you need additional clarifications. Feb 10 answered Explain “homotopy” to me Feb 7 comment Can we define structures like groups or monoids in the context of pure category theory? @JoshChen did you mean the commutative version? Feb 7 revised Can we define structures like groups or monoids in the context of pure category theory? Added remarks Feb 7 answered Can we define structures like groups or monoids in the context of pure category theory? Feb 5 comment Name for categories with a certain property on coproducts @ZhenLin if that's the case, well, it seems really hard to me that there are any interesting examples where the induced mappings between the hom-sets $\hom(Y,\bigoplus_{i \in I} X_i)$ and $\prod_{i \in I}\hom(Y,X_i)$ are injective....... Feb 5 comment Name for categories with a certain property on coproducts What are the projections maps? In a generic category with coproducts there is no reason why you should have natural mappings from $\bigoplus_{i \in I} X_i \to X_i$. Or am I missing something? Feb 2 comment Type theoretic proof that $\lnot (A \lor B) \Rightarrow \lnot A \land \lnot B$ Well in my opinion in this case one can use chat in an asynchronous way, it isn't really important to have an instant answer. Feb 1 comment Type theoretic proof that $\lnot (A \lor B) \Rightarrow \lnot A \land \lnot B$ By the way if you want to discuss this arguements I would be very interested, since I'm studying this subject too. Maybe via chat?! ;) Feb 1 comment Type theoretic proof that $\lnot (A \lor B) \Rightarrow \lnot A \land \lnot B$ Indeed, I supposed so. Feb 1 answered Type theoretic proof that $\lnot (A \lor B) \Rightarrow \lnot A \land \lnot B$ Feb 1 comment Example of Spherical Element (Simplicial Homotopy) AAAAAAAH Sorry I forgot you have degeracy maps in $\Delta$, so stupid by me. Again apologize for the confusion. Feb 1 comment Example of Spherical Element (Simplicial Homotopy) @NajibIdrissi is the simplicial set with only one $0$-simplex and no simplex in higher dimension. Clearly this cannot be a the terminal simplicial set.