English
If A,B: X → n → R are continuous, then their dot product A(x) ⬝ᵥ B(x) is continuous in x.
Русский
Если A,B: X → n → R непрерывны, то их скалярное произведение A(x) ⬝ᵥ B(x) непрерывно по x.
LaTeX
$$$\\operatorname{Continuous}(A) \\rightarrow \\operatorname{Continuous}(B) \\rightarrow \\operatorname{Continuous}(x \\mapsto A(x) \\;\\cdot\\; B(x)).$$$
Lean4
@[continuity, fun_prop]
protected theorem dotProduct [Fintype n] [Mul R] [AddCommMonoid R] [ContinuousAdd R] [ContinuousMul R] {A : X → n → R}
{B : X → n → R} (hA : Continuous A) (hB : Continuous B) : Continuous fun x => A x ⬝ᵥ B x :=
by
dsimp only [dotProduct]
fun_prop