def OrderedSpectrum.gap (spec : OrderedSpectrum M) (k : Fin M) (hk : (k : ℕ) + 1 < M) : ℝ := spec.rate k / spec.rate ⟨(k : ℕ) + 1, hk⟩
thesis/CESProofs/Hierarchy/SpectralHierarchy.lean:93
Endogenous Hierarchy: Why N Levels?