Assume production is described by Y = BK^alpha X^beta E^gamma L^1-alpha - beta - gamma, where K is capital, X is land, and E is energy. Capital evolves according to a typical Solow model, K^dot = sY - delta K. Land does not grow, X^dot = 0. Energy evolves according to E = s_ER_0e^-sE^t, meaning that energy use is steadily declining over time. Population evolves according to L^dot/L = n. Solve for the steady state growth rate of output per worker.