English
There is an induced ContMDiffMul structure, i.e., multiplication is smooth in the sense of ContMDiff, on ContMDiffRing.
Русский
Существует структура ContMDiffMul, т.е. умножение гладко в смысле ContMDiff, на ContMDiffRing.
LaTeX
$$$\\text{ContMDiffMul } I\,n\,R$$$
Lean4
instance (priority := 100) instFieldContMDiffRing {𝕜 : Type*} [NontriviallyNormedField 𝕜] {n : WithTop ℕ∞} :
ContMDiffRing 𝓘(𝕜) n 𝕜 :=
{ instNormedSpaceLieAddGroup with
contMDiff_mul := by
rw [contMDiff_iff]
refine ⟨continuous_mul, fun x y => ?_⟩
simp only [mfld_simps]
rw [contDiffOn_univ]
exact contDiff_mul }