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Theorems · Definition · combinatorics

Fintype.equivFinOfCardEq

{α : Type u_1} → [inst : Fintype α] → {n : ℕ} → Fintype.card α = n → α ≃ Fin n

If the cardinality of α is n, there is noncomputably a bijection between α and Fin n. See Fintype.truncEquivFinOfCardEq for the computable definition, and Fintype.truncEquivFin and Fintype.equivFin for the bijection α ≃ Fin (card α).

Defined in
Mathlib.Data.Fintype.EquivFin
Cited by
22 results in Mathlib
Foundations
Depth 60 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
Fintype

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