English
The quotient map from R / (a I) to R / (span {a}) is surjective.
Русский
Картирование по частному кольцу от R / (a I) к R / (a) покрывающее.
LaTeX
$$Function.Surjective (Ideal.quotOfMul a I)$$
Lean4
/-- The quotient map `(R ⧸ a • I) →ₗ[R] (R ⧸ Ideal.span {a})` is surjective.
-/
theorem quotOfMul_surjective {a : R} (I : Ideal R) : Function.Surjective (Ideal.quotOfMul a I) :=
by
simp only [Ideal.quotOfMul]
exact Submodule.factor_surjective <| Submodule.singleton_set_smul I a ▸ Submodule.smul_le_span { a } I