Documentation

Mathlib.SetTheory.Cardinal.Embedding

Existence of embeddings from finite types #

Let s : Set α be a finite set.

theorem Fin.Embedding.exists_embedding_disjoint_range_of_add_le_ENat_card {α : Type u_1} {n : } {s : Set α} [Finite s] (hs : s.ncard + n ENat.card α) :
∃ (y : Fin n α), Disjoint s (Set.range y)
theorem Fin.Embedding.exists_embedding_disjoint_range_of_add_le_Nat_card {α : Type u_1} {n : } {s : Set α} [Finite α] (hs : s.ncard + n Nat.card α) :
∃ (y : Fin n α), Disjoint s (Set.range y)
theorem Fin.Embedding.restrictSurjective_of_add_le_ENatCard {α : Type u_1} {m n : } (hn : m + n ENat.card α) :
Function.Surjective fun (x : Fin (m + n) α) => (castAddEmb n).trans x
theorem Fin.Embedding.restrictSurjective_of_add_le_natCard {α : Type u_1} {m n : } [Finite α] (hn : m + n Nat.card α) :
Function.Surjective fun (x : Fin (m + n) α) => (castAddEmb n).trans x