Goal:
  
  G1 : t
  G2 : t
  on_edge : forall x y : V.t, EdgeOf G1 x y -> EdgeOf G2 x y
  eos : CoreTactics.end_of_section
  fix_0 : forall (s : VSet.t) (x y : V.t) (p : SPath G1 s x y),
          map_spath_graph s x y p (map_spath p)
  ============================
   (forall (s : VSet.t) (x y : V.t) (p : SPath G1 s x y),
    map_spath_graph s x y p (map_spath p))


DEBUG:Going to execute:
match goal with
           | H:_ /\ _ |- _ => destruct H
           | H:(_ * _)%nat |- _ => destruct H
           | H:?X -> _, H':?X
             |- _ => match X with
                     | _ -> _ => specialize (H H')
                     end
           | H:?A /\ ?B -> ?C |- _ => apply (uncurry_conj A B C) in H
           end