no goals
ι : Type ?u.68209
α : Type u_1
β : Type ?u.68215
π : ι → Type ?u.68220
inst✝ : GeneralizedBooleanAlgebra α
a b c d : α
⊢ a \ (b ⊔ c) ⊔ b \ (a ⊔ c) ⊔ (c \ (a ⊔ b) ⊔ c ⊓ a ⊓ b) = a \ (b ⊔ c) ⊔ b \ (a ⊔ c) ⊔ c \ (a ⊔ b) ⊔ a ⊓ b ⊓ c
ac_rfl