Goal:
  
  G : t
  x : V.t
  y : V.t
  z : V.t
  e : EdgeOf x y
  q : PathOf y z
  IHq : forall (s : VSet.t) (p : SPath s z y) (s' : VSet.t)
          (Hs : VSet.Equal (VSet.union s (nodes q)) s'),
        0 < weight q + sweight p -> 0 < sweight (simplify q p Hs).π2
  s : VSet.t
  p : SPath s z x
  s' : VSet.t
  Hs : VSet.Equal (VSet.union s (nodes (pathOf_step e q))) s'
  p1 : SPath (VSet.remove x s) z x
  p2 : SPath s x x
  H : 0 < e.π1 + weight q + (sweight p1 + sweight p2)
  F0 : true = false -> ~ VSet.In x s
  F1 : true = true -> VSet.In x s
  F2 : true = true ->
       forall s1 s2 : VSet.t,
       VSet.Equal (VSet.union s (VSet.add x s1)) s2 ->
       VSet.Equal (VSet.union s s1) s2
  Hp : split' p = (p1, p2)
  eq : sweight p2 <= 0
  X : sweight p1 + sweight p2 = sweight p
  ============================
   (0 < weight q + (sweight p1 + e.π1))


DEBUG:Going to execute:
intros; Zify.zify_pre_hook; zify_elim_let; zify_op;
            Zify.zify_iter_specs; Zify.zify_to_euclidean_division_equations;
            Zify.zify_post_hook; zify_saturate