rw [h] at hp
graph✝ : Graph
a✝ : Class graph✝
path₁ path₂ : Path graph✝ a✝
h : prefix? path₁ = prefix? path₂
hp : Option.isSome (prefix? path₁) = true
w✝ : Path graph✝ a✝
hp₁ : prefix? path₁ = some w✝
⊢ path₁ ≂ path₂
graph✝ : Graph
a✝ : Class graph✝
path₁ path₂ : Path graph✝ a✝
h : prefix? path₁ = prefix? path₂
hp : Option.isSome (prefix? path₂) = true
w✝ : Path graph✝ a✝
hp₁ : prefix? path₁ = some w✝
⊢ path₁ ≂ path₂