Goal:
  
  G : t
  l : labelling
  Gl := relabel G l : t
  x : V.t
  y : V.t
  _x_ : V.t
  cstr : 0 <= Z.of_nat (l _x_)
  ============================
   (0 = Z.of_nat (l _x_) - Z.of_nat (l _x_))


DEBUG:Going to execute:
idtac
DEBUG LTAC Evaluated term: false
DEBUG LTAC Evaluated term: false
Level 2: Zify.zify_convert_to_euclidean_division_equations_flag
 has value 
false

Level 2: Zify.zify_convert_to_euclidean_division_equations_flag
 has value 
false