In mathematics, specifically category theory, an overcategory (and undercategory) is a distinguished class of categories used in multiple contexts, such...

{\displaystyle \pi :E\to X} be the natural projection. Consider the overcategory Top / X {\displaystyle {\text{Top}}/X} of topological spaces over X {\displaystyle...

( A ∖ R ) / B {\displaystyle (A\backslash R)/B} be the associatived overcategory of objects in A ∖ R {\displaystyle A\backslash R} , then an H-object...

{\displaystyle {\mathcal {X}}} is a category fibered in groupoids, meaning the overcategory for some π : X → S {\displaystyle \pi :X\to S} is a groupoid The diagonal...

{\displaystyle I} is a B {\displaystyle B} -module. Then, there is an overcategory denoted Exal _ A {\displaystyle {\underline {\text{Exal}}}_{A}} (meaning...