[∀ x.A]1                   [∀x. (A→B)]2
------------- (∀E)       ------------------- (∀E)
   A                              A→B
 -------------------------------------- (→E)
                B
            ---------- (∀I)
               ∀x.B
         ----------------- (→I) (1)
          (∀x.A) → (∀y.B)
------------------------------------------  (→I)(2)
   (∀x. (A→B)) → ( (∀x.A) → (∀y.B))