theorem scale_scope_complementarity {γ ρ : ℝ} (hγ : 1 < γ) (hρ : ρ < 1) :
0 < scaleScopeCrossPartialSign γ ρ := by
simp only [scaleScopeCrossPartialSign]
apply mul_pos
· apply mul_pos <;> linarith
· linarithIncreasing returns to scale results (Paper 1, Section 11):