Theorems · Theorem · group theory

Finset.prod_biUnion_of_pairwise_eq_one

∀ {ι : Type u_1} {κ : Type u_2} {M : Type u_4} [inst : CommMonoid M] {f : ι → M} [inst_1 : DecidableEq ι] {s : Finset κ}
  {t : κ → Finset ι},
  ((↑s).Pairwise fun i j => ∀ k ∈ t i ∩ t j, f k = 1) → ∏ x ∈ s.biUnion t, f x = ∏ x ∈ s, ∏ i ∈ t x, f i

Defined in

Mathlib.Algebra.BigOperators.Group.Finset.Basic

Cited by

0 results in Mathlib

Foundations

Depth 76 from the axioms · uses propext, Classical.choice, Quot.sound

Assumes

CommMonoidDecidableEq