Theorems · Theorem · combinatorics

Finset.filter_piFinset_eq_map_insertNthEquiv

∀ {n : ℕ} {α : Fin (n + 1) → Type u_1} {p : Fin (n + 1)} (S : (i : Fin (n + 1)) → Finset (α i))
  (P : ((i : Fin n) → α (p.succAbove i)) → Prop) [inst : DecidablePred P],
  {r ∈ Fintype.piFinset S | P (p.removeNth r)} =
    Finset.map (Fin.insertNthEquiv α p).toEmbedding (S p ×ˢ {r ∈ Fintype.piFinset (p.removeNth S) | P r})

Defined in

Mathlib.Data.Fin.Tuple.Finset

Cited by

0 results in Mathlib

Foundations

Depth 71 from the axioms · uses propext, Classical.choice, Quot.sound

Assumes

DecidablePred