theorem damping_cancellation_algebraic {phi_prev sigma_n c_n : ℝ} (hsigma : sigma_n ≠ 0) : c_n * (phi_prev / sigma_n) * sigma_n = c_n * phi_prev := by field_simp
thesis/CESProofs/Hierarchy/DampingCancellation.lean:60
Proposition 6, Theorem 9, Corollaries 1-2 and 4: