simp [andN, notList, map]
l : List Prop
h₁ h₂ : Prop
t : List Prop
h : h₁ ∨ orN (h₂ :: t) → False
t₁ : ¬h₁
t₂ : orN (h₂ :: t) → False
⊢ andN (notList (h₁ :: h₂ :: t))
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)