exact reachable_from_list.step x e ih_1 ih_2 ih_4
Node : Type
inst✝ : DecidableEq Node
g : Graph Node
xs ys : List Node
h1 : xs ⊆ ys
x✝ x : Node
e : Node × List Node
ih_1 : e ∈ g
ih_2 : x ∈ e.2
a✝ : reachable_from_list g xs e.1
ih_4 : e.1 ∈ reachable_from_list g ys
⊢ x ∈ reachable_from_list g ys
no goals