new (C ∨ A → A) → ((C → B ∧ E) → (((B → G) → B) → (H ∧ B → (H ∨ G → (C → (F ∧ E → ((F → B) → A ∧ F)))))))
intro
intro
intro
intro
cases 3
intro
intro
intro
cases 8
intro
cases 3
cases 8
constructor
apply 0
left
exact 7
exact 9