no goals
ι : Type ?u.69972
α : Type u_1
β : Type ?u.69978
π : ι → Type ?u.69983
inst✝ : GeneralizedBooleanAlgebra α
a b c d : α
⊢ a \ (b ⊔ c) ⊔ a ⊓ b ⊓ c ⊔ (b \ (c ⊔ a) ⊔ c \ (b ⊔ a)) = a \ (b ⊔ c) ⊔ b \ (a ⊔ c) ⊔ c \ (a ⊔ b) ⊔ a ⊓ b ⊓ c
ac_rfl