Goal:
  
  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:
<coq-core.plugins.ltac::intro@1> $1

Goals:
    G : t  z : V.t  x : V.t  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
  q : PathOf z0 z
  ============================
   (weight (concat (pathOf_step e p) q) = weight (pathOf_step e p) + weight q)


DEBUG:Going to execute:
cbn