∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] {FC : C → C → Type u_1} {CC : C → Type w}
  [inst_1 : (X Y : C) → FunLike (FC X Y) (CC X) (CC Y)] [inst_2 : CategoryTheory.ConcreteCategory C FC] {X Y : C}
  (f : X ⟶ Y)
  [CategoryTheory.Limits.PreservesColimitsOfShape CategoryTheory.Limits.WalkingSpan (CategoryTheory.forget C)],
  CategoryTheory.Epi f ↔ Function.Surjective ⇑(CategoryTheory.ConcreteCategory.hom f)