Goal:
    G : t  HI : invariants G  HG : acyclic_no_loop G  n : Z  x : V.t  y : V.t
  ============================
   (V.eq_dec x y || le_dec (Some n) (lsp G x (s G)) <->
    x = y \/ (Some n <= lsp G x (s G))%nbar)


DEBUG:Going to execute:
etransitivity
DEBUG LTAC Evaluated term: andb_and
DEBUG LTAC Evaluated term: Morphisms_Prop.and_iff_morphism
DEBUG LTAC Evaluated term: Z.leb_le