Goal:
  
  G1 : t
  G2 : t
  sub : full_subgraph G1 G2
  x : VSet.elt
  hx : VSet.In x (V G1)
  y : VSet.elt
  hy : VSet.In y (V G1)
  _x_ : V.t
  _y_ : V.t
  _x1_ : Z
  _p_ : EdgeSet.In (_x_, _x1_, _y_) (E G1)
  ============================
   (_x1_ >= _x1_)


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