Snevily's conjecture on Latin transversals
DefinitionSnevily's conjecture#✓fully proved
The statement that for every finite abelian group \(G\) of odd order, written additively, and all subsets \(A, B \subseteq G\) with \(|A| = |B|\), there is a bijection \(f \colon A \to B\) such that the sums \(a + f(a)\), for \(a \in A\), are pairwise distinct.
Equivalently, \(A\) and \(B\) can be enumerated as \(a_1, \dots, a_k\) and \(b_1, \dots, b_k\) so that the sums \(a_i + b_i\) are pairwise distinct: given such enumerations, send \(a_i\) to \(b_i\); conversely, enumerate \(A\) and transport the enumeration along \(f\).
def conjecture : Prop :=
∀ (G : Type) [AddCommGroup G] [Fintype G],
Odd (Fintype.card G) →
∀ A B : Finset G, A.card = B.card →
∃ f : ↥A → ↥B, Function.Bijective f ∧
∀ a₁ a₂ : ↥A,
(a₁ : G) + (f a₁ : G) = (a₂ : G) + (f a₂ : G) → a₁ = a₂
Sources
- OPG-655.
Used by 1
TheoremSnevily's conjecture is true#●ready to prove
Let \(G\) be a finite abelian group of odd order, written additively, and let \(A, B \subseteq G\) be subsets with \(|A| = |B|\). Then there is a bijection \(f \colon A \to B\) such that the sums \(a + f(a)\), for \(a \in A\), are pairwise distinct.
public theorem_wanted conjecture_holds : conjecture
def conjecture : Prop :=
∀ (G : Type) [AddCommGroup G] [Fintype G],
Odd (Fintype.card G) →
∀ A B : Finset G, A.card = B.card →
∃ f : ↥A → ↥B, Function.Bijective f ∧
∀ a₁ a₂ : ↥A,
(a₁ : G) + (f a₁ : G) = (a₂ : G) + (f a₂ : G) → a₁ = a₂
WantedExt/Combinatorics/SnevilyTransversalWanted.lean:34
Sources
- Boris Arsovski, A proof of Snevily's conjecture, Israel J. Math. 182 (2011), 505-508.
Uses 1
Loading dependency explorer…
The dependency explorer needs JavaScript and its graph data.