induction p with
| nil => simp
| cons _ _ ih =>
  rw [Walk.cons_isPath_iff] at hp
  simp [ih hp.1]
  intro x hx hf
  cases hinj hf
  exact hp.2 hx
V : Type u
V' : Type v
V'' : Type w
G : Digraph V
G' : Digraph V'
G'' : Digraph V''
f : G →g G'
f' : G' →g G''
u v u' v' : V
p : Walk G u v
hinj : Injective ↑f
hp : IsPath p
⊢ IsPath (Walk.map f p)
no goals