definition category.id [reducible] : Π {ob : Type} [C : precategory ob] {a : ob}, hom a a := ID definition function.id [reducible] : Π {A : Type}, A → A := λ (A : Type) (a : A), a ----------- definition category.id [reducible] : Π {ob : Type} [C : precategory ob] {a : ob}, hom a a ID definition function.id [reducible] : Π {A : Type}, A → A λ (A : Type) (a : A), a