induction p with
| nil => simp
| cons _ _ ih =>
  simp only [Walk.transfer, cons_isPath_iff, support_transfer _ ] at pp ⊢
  exact ⟨ih _ pp.1, pp.2⟩
V : Type u
V' : Type v
V'' : Type w
G : Digraph V
G' : Digraph V'
G'' : Digraph V''
u v : V
p : Walk G u v
H : Digraph V
hp : ∀ (e : V × V), e ∈ edges p → e ∈ edgeSet H
pp : IsPath p
⊢ IsPath (Walk.transfer p H hp)
no goals