English
Mapping distributes over addition: for any f between additive structures, map f on a + b equals map f on a plus map f on b.
Русский
Переображение через отображение публикует сложение: map f(a + b) = map f a + map f b.
LaTeX
$$$\\\\forall {F} [Add β] [FunLike F α β] [AddHomClass F α β] (f : F) (a b : WithTop α), (a + b).map f = a.map f + b.map f$$$
Lean4
@[simp]
protected theorem map_add {F} [Add β] [FunLike F α β] [AddHomClass F α β] (f : F) (a b : WithTop α) :
(a + b).map f = a.map f + b.map f := by
induction a
· exact (top_add _).symm
· induction b
· exact (add_top _).symm
· rw [map_coe, map_coe, ← coe_add, ← coe_add, ← map_add]
rfl