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