diff --git a/draft/draft.tex b/draft/draft.tex index b2621fe..40362d2 100644 --- a/draft/draft.tex +++ b/draft/draft.tex @@ -2298,18 +2298,19 @@ Having lax versions of a symmetric relator, allows us to have simulation relatio \begin{lemma} Given objects $A$, $X$, and $Y$ in a category $\BC$, then we have: \begin{gather*} - \Hom(X,Y)\iso \Hom(\Hom(A,X)\to\Hom(A,Y)) + \Hom(X,Y)\iso \Hom(\Hom(A,X),\Hom(A,Y)) \end{gather*} \end{lemma} \begin{proof} - It is entailed by the Yoneda lemma. \todo{Finish! You may need cartesian closedness!} -\end{proof} -\begin{cor} - Given objects $X$ and $Y$ in a category $\BC$, then we have: + It is entailed by the Yoneda lemma. The contravariant version of the Yoneda's lemma says that given a functor $G\c\BC^\op\to\Set$ the following correspondance holds: \begin{gather*} - \Hom(X,Y)\iso \Hom(\Hom(1,X)\to\Hom(1,Y)) + GX\iso\Hom(\Hom(\argument,X),G) \end{gather*} -\end{cor} + If we substitute $G$ with $\Hom(\argument,Y)$ then we have the following: + \begin{gather*} + \Hom(\argument,Y)\iso\Hom(\Hom(\argument,X),\Hom(\argument,Y)) + \end{gather*} +\end{proof} % \begin{prop} Assuming the axiom of choice, given $(X_1 \stackrel{p_1}{\leftarrow} R \stackrel{p_2}{\to}X_2)$ and $(Y_1 \stackrel{q_1}{\leftarrow} S \stackrel{q_2}{\to}Y_2)$, there is a morphism $(g_1,g_2,w)\c(X_1 \stackrel{p_1}{\leftarrow} R \stackrel{p_2}{\to}X_2)\to(Y_1 \stackrel{q_1}{\leftarrow} S \stackrel{q_2}{\to}Y_2)$ in $\spa(\BC)$ iff there is a morphism $(g_1,g_2)\c(X_1 \stackrel{p_1}{\leftarrow} R \stackrel{p_2}{\to}X_2)\to(Y_1 \stackrel{q_1}{\leftarrow} S \stackrel{q_2}{\to}Y_2)$ in $\spa(\BC)$.