Formal target: Corpus.Erdos274.herzog_schonheim
Let $G$ be a group, and let $A = \{a_1G_1, \dots, a_kG_k\}$ be a finite system of left cosets of subgroups $G_1, \dots, G_k$ of $G$.
Exact formal statement
∀ {G : Type u_1} [inst : Group.{u_1} G],
LT.lt.{0} 1 (ENat.card.{u_1} G) →
∀ {ι : Type u_2} [inst_1 : Fintype.{u_2} ι],
LT.lt.{0} 1 (Fintype.card.{u_2} ι) →
∀ (P : Corpus.Erdos274.Group.ExactCovering.{u_1, u_2} G ι),
Exists.{u_2 + 1} fun i =>
Exists.{u_2 + 1} fun j =>
And (Ne.{u_2 + 1} i j)
(Eq.{1} (Subgroup.index.{u_1} (Corpus.Erdos274.Group.ExactCovering.parts.{u_1, u_2} P i))
(Subgroup.index.{u_1} (Corpus.Erdos274.Group.ExactCovering.parts.{u_1, u_2} P j)))This target is a formal statement, not a proof of the problem.
Environment availability: available.