new A ∨ E → (B ∨ A → (B ∨ A → ((((B ∧ D) ∧ ((C ∨ E) ∧ C)) ∧ (D ∨ B) → (E ∧ B) ∧ ((C ∧ D) ∧ A)) → (E → E) ∨ B)))
intro
intro
intro
intro
left
intro
exact 4