English
Embedding of a subtype inside a dense embedding is itself dense.
Русский
Вложение подмножества внутрь плотного вложения образует плотное вложение.
LaTeX
$$$IsDenseEmbedding.subtypeEmb p e \\text{ is dense embedding for any } p, e$$$
Lean4
/-- The product of two dense embeddings is a dense embedding. -/
protected theorem prodMap {e₁ : α → β} {e₂ : γ → δ} (de₁ : IsDenseEmbedding e₁) (de₂ : IsDenseEmbedding e₂) :
IsDenseEmbedding fun p : α × γ => (e₁ p.1, e₂ p.2)
where
toIsDenseInducing := de₁.isDenseInducing.prodMap de₂.isDenseInducing
injective := de₁.injective.prodMap de₂.injective