new A → (E ∧ J → ((E ∨ B → D) → (A ∧ B → (H → (C → ((((B → D) → B ∨ I) ∨ A) ∨ E) ∧ B)))))
intro
intro
cases 1
intro
intro
cases 5
intro
intro
cases 1
cases 5
constructor
left
left
intro
cases 1
cases 5
left
exact 7
exact 7