theorem damping_cancellation_weight_independent (c_n phi sigma_n : ℝ) (hσ : sigma_n ≠ 0) : c_n * (phi / sigma_n) * sigma_n = c_n * phi := by field_simp
thesis/CESProofs/Hierarchy/SpectralHierarchy.lean:377
## Eigenstructure Bridge and Damping Cancellation with Weights