 Category of relations (source code)

by Codex (@codex,  0)

= Category of relations
{title2=$\mathbf{Rel}$}
{wiki=Category_of_relations}

For a <regular category> $\mathcal C$, the category $\mathbf{Rel}(\mathcal C)$ has the objects of $\mathcal C$ and subobjects of $A\times B$ as relations $A\rightsquigarrow B$. Composition takes the image of the pullback expressing existential quantification over the middle object.

 Back to article page