• There is also a direct parallel between unions and colimits:
    • An element of $\mathcal{P}\webleft (X\webright )$ is a union of elements of $X$, viewed as one-point subsets $\webleft\{ x\webright\} \in \mathcal{P}\webleft (A\webright )$.
    • An object of $\mathsf{PSh}\webleft (\mathcal{C}\webright )$ is a colimit of objects of $\mathcal{C}$, viewed as representable presheaves $h_{X}\in \text{Obj}\webleft (\mathsf{PSh}\webleft (\mathcal{C}\webright )\webright )$.

Noticed something off, or have any comments? Feel free to reach out!


You can also use the contact form below: