Goal:
    G : t  x : V.t  y : V.t  z : V.t  p : PathOf x y
  ============================
   (forall q : PathOf y z, weight (concat p q) = weight p + weight q)


DEBUG:Going to execute:
induction p

Goals:
    G : t  z : V.t  x : V.t
  ============================
   (forall q : PathOf x z,
    weight (concat (pathOf_refl x) q) = weight (pathOf_refl x) + weight q)

  
  G : t
  z : V.t
  x : V.t
  y : V.t
  z0 : V.t
  e : EdgeOf x y
  p : PathOf y z0
  IHp : forall q : PathOf z0 z, weight (concat p q) = weight p + weight q
  ============================
   (forall q : PathOf z0 z,
    weight (concat (pathOf_step e p) q) = weight (pathOf_step e p) + weight q)


DEBUG:Going to execute:
intro q
DEBUG LTAC Evaluated term: p