English
In the setting of a Pi-algebra, the action of mkPiAlgebra on a family m: ι → A simply equals the product ∏ i∈ι m_i.
Русский
В настройке Pi-алгебры действие mkPiAlgebra на семейство m: ι → A равно произведению ∏_{i} m_i.
LaTeX
$$$\\operatorname{mkPiAlgebra} \\; R\\ ι\\ A\\ m = \\prod i \\; m_i.$$$
Lean4
/-- Multiplicativity of a multilinear map along all coordinates at the same time,
writing `f (fun i => c i • m i)` as `(∏ i, c i) • f m`. -/
theorem map_smul_univ [Fintype ι] (c : ι → R) (m : ∀ i, M₁ i) : (f fun i => c i • m i) = (∏ i, c i) • f m := by
classical simpa using map_piecewise_smul f c m Finset.univ