definition id [reducible] [unfold_full] : Π {A : Type}, A → A := λ (A : Type) (a : A), a definition category.id [reducible] [unfold 1] : Π {ob : Type} [C : precategory ob] {a : ob}, hom a a := ID ----------- definition id [reducible] [unfold_full] : Π {A : Type}, A → A λ (A : Type) (a : A), a definition category.id [reducible] [unfold 1] : Π {ob : Type} [C : precategory ob] {a : ob}, hom a a ID