exists pre
graph✝ : Graph
cls✝ : Class graph✝
child : Class.Child cls✝
path₁ : Path graph✝ (Class.Child.class child)
pre : Path graph✝ cls✝
h : prefix? (Path.cons child path₁) = some pre
⊢ ∃ path₂, Path.cons child path₁ ≻ path₂
no goals