mathlib3

56adee5b - feat(combinatorics/quiver/single_obj): single object quivers (#17846)

feat(combinatorics/quiver/single_obj): single object quivers (#17846) I think it makes sense for `category_theory/single_obj` to depend on `combinatorics/quiver/single_obj`, but I'd like to know what people working with category theory think of that. Co-authored by: Remi Bottinelli https://github.com/bottine Co-authored-by: antoinelab01 <66086247+antoinelab01@users.noreply.github.com> Co-authored-by: Antoine Labelle <antoinelab01@gmail.com> Co-authored-by: Rémi Bottinelli <bottine@users.noreply.github.com>