Goal:
    G : t  HI : invariants  HG : acyclic_no_loop  x : V.t  y : V.t  z : V.t
  ============================
   (lsp x y + lsp y z <= lsp x z)%nbar


DEBUG:Going to execute:
generalize eq_refl; pattern x at - 1
Level 1: evaluation returns
generalize eq_refl; pattern x at - 1; case x
where
x := lsp x y
of type
constr of type tacvalue