Goal:
  
  ============================
   (∀ (A B : Type) (l : list A) (f : ∀ x : A, In x l → B),
      map_In_graph A B l f (map_In l f))


DEBUG:Going to execute:
let eos := fresh "eos" in
           pose proof CoreTactics.the_end_of_the_section as eos