theorem dtcPremium_complement_regime {α σ : ℝ}
(hα : 0 < α) (hα1 : α < 1) (hσ : σ < 2)
{K₁ K₂ L : ℝ} (hK₁ : 0 < K₁) (hK₂ : 0 < K₂) (hL : 0 < L)
(hK : K₁ < K₂) :
(α / (1 - α)) * (K₂ / L) ^ (σ - 2) <
(α / (1 - α)) * (K₁ / L) ^ (σ - 2) := by
have hα_rat : 0 < α / (1 - α) := div_pos hα (by linarith)
apply mul_lt_mul_of_pos_left _ hα_rat
have hσ2 : σ - 2 < 0 := by linarith
exact (Real.rpow_lt_rpow_iff_of_neg (div_pos hK₂ hL) (div_pos hK₁ hL) hσ2).mpr
(div_lt_div_of_pos_right hK hL)Directed Technical Change Extension (Acemoglu 2002)