theorem equilibriumShare_sum [NeZero J]
(a cost : Fin J → ℝ)
(hω : 0 < ∑ k : Fin J, agentFitness a cost ρ k) :
∑ j, equilibriumShare a cost ρ j = 1 := by
unfold equilibriumShare
rw [← Finset.sum_div]
exact div_self (ne_of_gt hω)Multi-Agent CES Game Theory (Gap #14)