Definition 6.82. (Shape)

The shape \(\abs{T}\) of a topos \(T\) is the relative shape of the terminal morphism \(\Gamma_*\colon T \to \An\):

\[\abs{T} \quad:=\quad \abs{\Gamma_*} \qin \Pro(\An).\]

We say that \(T\) has constant shape if the pro-anima \(\abs{T}\) is pro-constant. We say that an object \(X \in T\) has constant shape if the slice topos \(T_{/X}\) does.