theorem correlation_above_floor {r : ℝ} {J : ℕ} (hJ : 2 ≤ J) (hr : 0 ≤ r) :
-1 / (↑J - 1) < compoundSymmetryCorr r J := by
have h := correlation_floor_identity hJ hr
have hJ1 := hJ_sub_one_pos hJ
have hden := den_pos hJ hr
have hJp : (0 : ℝ) < ↑J := Nat.cast_pos.mpr (by omega)
have key : 0 < compoundSymmetryCorr r J + 1 / (↑J - 1) := by
rw [h]; exact div_pos hJp (mul_pos hJ1 hden)
have neg_cancel : (-1 : ℝ) / (↑J - 1) + 1 / (↑J - 1) = 0 := by
rw [← add_div]; simp
linarithCorrelation Convergence at the Regime Boundary