simp [hp]
t : Prop
l : List Prop
ih : ∀ {ps : List Prop} {i j : Nat}, orN ps → ps = drop i (take j l) → orN l
ps : List Prop
j : Nat
hps : ps = drop 0 (t :: take j l)
hp✝ : t ∨ orN (take j l)
hp : orN (take j l)
⊢ orN (drop 0 (take j l))
no goals