Goal:
  
  G : t
  HI : invariants G
  HG : acyclic_no_loop G
  n : Z
  x : V.t
  y : VSet.elt
  Vy : VSet.In y (V G)
  m : Z
  p : SPath G (V G) x y
  Hp : sweight p = m
  l : labelling
  Hl : correct_labelling G l
  Hle : (Some n <= Some m)%nbar
  XX : Z.of_nat (l x) + m <= Z.of_nat (l y)
  ============================
   (Z.of_nat (l x) + n <= Z.of_nat (l y))


DEBUG:Going to execute:
cbn in Hle
DEBUG LTAC Evaluated term: Hm
DEBUG LTAC Evaluated term: Hm
DEBUG LTAC Evaluated term: (lsp0_spec_eq G)
DEBUG LTAC Evaluated term: Hm
DEBUG LTAC Evaluated term: (correct_labelling_PathOf G l Hl x y
                              (to_pathOf G p))
DEBUG LTAC Evaluated term: sweight_weight
DEBUG LTAC Evaluated term: sweight_weight
DEBUG LTAC Evaluated term: Hp
DEBUG LTAC Evaluated term: Hp