theorem sectorMultiplier_pos (e : NSectorEconomy N) (n : Fin N) : 0 < sectorMultiplier e n := by unfold sectorMultiplier exact mul_pos (sectorCurvature_pos e n) (e.hd n)
thesis/CESProofs/Dynamics/MultiplierCycles.lean:73
Multiplier-Cycle Duality in a Multi-Sector Economy