Goal:
  
  G : t
  HI : invariants
  HG : acyclic_no_loop
  x : V.t
  y : V.t
  z : V.t
  n : Z
  Hn : lsp x y = Some n
  m : Z
  Hm : lsp y z = Some m
  p1 : SPath (V G) x y
  Hp1 : sweight p1 = n
  p2 : SPath (V G) y z
  Hp2 : sweight p2 = m
  XX : (Some (sweight (simplify2' (concat (to_pathOf p1) (to_pathOf p2)))) <=
        lsp0 (V G) x z)%nbar
  H : n + m <= sweight (simplify2' (concat (to_pathOf p1) (to_pathOf p2)))
  ============================
   (Some (n + m)%Z <= lsp x z)%nbar


DEBUG:Going to execute:
etransitivity
DEBUG LTAC Evaluated term: Hp1
DEBUG LTAC Evaluated term: Hp1
DEBUG LTAC Evaluated term: Hp2
DEBUG LTAC Evaluated term: Hp2