new ((E → G) → G) → (C → ((A → E) → (C ∧ E → (E ∧ C → (A ∧ (D ∨ C) ∨ (B ∨ E)) ∨ D))))
intro
intro
intro
intro
cases 3
intro
cases 6
cases 3
cases 6
left
right
right
exact 5