new F ∧ C → ((H → G ∧ A) → ((A ∨ D → B) → ((F → H) → (E ∧ F → (E → (A → E) ∧ (H ∨ E))))))
intro
cases 0
intro
intro
intro
intro
cases 6
intro
cases 0
cases 6
constructor
intro
cases 0
cases 6
exact 7
left
apply 5
exact 1