English
Alternative articulation: the same range description for toProd, emphasizing the equality condition ∀ x,y.
Русский
Альтернативная формулировка: то же описание образа toProd через условие ∀ x,y.
LaTeX
$$$$ \\operatorname{range}(\\mathrm{toProd}) = \\{ (l,r) \\mid \\forall x,y, r(x) \\cdot y = x \\cdot l(y) \\} $$$$
Lean4
instance instAdd : Add 𝓜(𝕜, A) where
add a
b :=
{ toProd := a.toProd + b.toProd
central := fun x y =>
show (a.snd + b.snd) x * y = x * (a.fst + b.fst) y by
simp only [ContinuousLinearMap.add_apply, mul_add, add_mul, central] }