have ih := @deMorgan₃ (h₂::t) t₂
l : List Prop
h₁ h₂ : Prop
t : List Prop
h : h₁ ∨ orN (h₂ :: t) → False
t₁ : ¬h₁
t₂ : orN (h₂ :: t) → False
⊢ ¬h₁ ∧ andN ((¬h₂) :: map Not t)
l : List Prop
h₁ h₂ : Prop
t : List Prop
h : h₁ ∨ orN (h₂ :: t) → False
t₁ : ¬h₁
t₂ : orN (h₂ :: t) → False
ih : andN (notList (h₂ :: t))
⊢ ¬h₁ ∧ andN ((¬h₂) :: map Not t)