new D → (D ∧ A → ((D ∨ E) ∨ B → ((C → D) → ((G → G) ∨ D ∧ E → (D ∨ E → (G → G) ∨ (D ∨ G))))))
intro
intro
cases 1
intro
intro
intro
intro
cases 1
left
intro
cases 1
exact 10