We can usually build new categories from old ones, as example we have the slice $\mathfrak C/A$ and coslice categories $A/\mathfrak C$ of $\mathfrak C$ with an object $A$. I'm reading this book and I'm looking for the name of this new from the category $\mathfrak C$ with its standard symbol:
Thanks
It is the category of cones over the diagram $\{0,1\} \to \mathsf C : 0 \mapsto A, 1 \mapsto B$. I don't think there is a standard notation for it.