English
There is a natural-scalar action on the quotient c.Quotient by n ∈ ℕ defined by [x] ↦ [n • x].
Русский
На фактор-модуле по конгруэнции c действует скалярами из ℕ: n • [x] = [n • x].
LaTeX
$$$\\text{There exists an action }\\mathrm{SMul}_\\mathbb{N} : \\mathbb{N} \\curvearrowright c.\\Quotient\\;\\text{defined by } n\\cdot [x] = [n\\cdot x]$$$
Lean4
instance _root_.AddCon.Quotient.nsmul {M : Type*} [AddMonoid M] (c : AddCon M) : SMul ℕ c.Quotient where
smul n := (Quotient.map' (n • ·)) fun _ _ => c.nsmul n