`BookProof.ChapterPinOmega.Omega_mul_closed` : ∀ x ∈ Omega, ∀ y ∈ Omega, x * y ∈ Omega
ProvedBookProof.ChapterPinOmega.Omega_mul_closedtheoremstimepiece
Prove the following Lean 4 theorem from ChapterPinOmega.
BookProof.ChapterPinOmega.Omega_mul_closed : ∀ x ∈ Omega, ∀ y ∈ Omega, x * y ∈ Omega
Formalization note: Lean 4 identifier BookProof.ChapterPinOmega.Omega_mul_closed.
Preamble
-- Generated from ChapterPinOmega.lean — theorem BookProof.ChapterPinOmega.Omega_mul_closed import Definitions.Def_ChapterA3 import Mathlib import Definitions.Def_ChapterPinOmega import Definitions.Def_ChapterPinDoubleCover open BookProof.ChapterPinDoubleCover open BookProof.ChapterPinOmega open Matrix open BookProof.ChapterA3
Formal statement
theorem BookProof.ChapterPinOmega.Omega_mul_closed : ∀ x ∈ Omega, ∀ y ∈ Omega, x * y ∈ Omega := by sorry