α : Type u_1
inst✝ : CoheytingAlgebra α
a✝ b✝ a b : α
⊢ a ⊓ b ⊓ ￢(a ⊓ b) = a ⊓ ￢a ⊓ b ⊔ a ⊓ (b ⊓ ￢b)
α : Type u_1
inst✝ : CoheytingAlgebra α
a✝ b✝ a b : α
⊢ ∂ (a ⊓ b) = ∂ a ⊓ b ⊔ a ⊓ ∂ b
unfold boundary
no goals
α : Type u_1
inst✝ : CoheytingAlgebra α
a✝ b✝ a b : α
⊢ a ⊓ b ⊓ ￢(a ⊓ b) = a ⊓ ￢a ⊓ b ⊔ a ⊓ (b ⊓ ￢b)
rw [hnot_inf_distrib, inf_sup_left, inf_right_comm, ← inf_assoc]