theorem curvatureK_real_pos {J ρ : ℝ} (hJ : 1 < J) (hρ : ρ < 1) :
0 < curvatureK_real J ρ := by
simp only [curvatureK_real]
apply div_pos
· exact mul_pos (by linarith) (by linarith)
· linarithPaper 1c, Section 2: K(J) as the Network Engine