theorem cesCriticalStep_via_curvatureK {J : ℕ} (hJ : 2 ≤ J) {ρ : ℝ} (hρ : ρ < 1)
{c : ℝ} (hc : 0 < c) :
cesCriticalStep J ρ c = 2 * (↑J - 1) * c / curvatureK J ρ := by
rw [cesCriticalStep_eq (by omega) hρ hc]
simp only [curvatureK]
have hJpos : (0 : ℝ) < ↑J := by exact_mod_cast (show 0 < J by omega)
have hJne : (↑J : ℝ) ≠ 0 := ne_of_gt hJpos
have hJ1ne : (↑J : ℝ) - 1 ≠ 0 := by
have : (1 : ℝ) < ↑J := by exact_mod_cast (show 1 < J by omega)
linarith
have hρne : (1 : ℝ) - ρ ≠ 0 := by linarith
have hcne : c ≠ 0 := ne_of_gt hc
field_simpDiscrete-Time Stability of CES Tâtonnement (Edge of Stability)