Equations having form (1) arise as first-order conditions in microeconomic constrained optimization models, as defining characterizations for general equilibrium and macroeconomic models, and as steady-state solution characterizations for descriptive and optimal growth models. (See Silberberg [12], Hansen [7], Cass and Shell [3], and Brock [l].) If Y :R"' -+ R" is continuously differentiable ov...