“…To this effect let Ω = (0, T ) × Ω n −1 with Ω n −1 having a smooth boundary Γ, and distinguish the first variable t 1 in t as time and t 2 , … , t n as space variables. Consider the problem of optimal capital accumulation in a onesectoral economy . The economy has one capital good x ( t ), and n consumption goods C ( t ) = ( C 1 ( t ), … , C n ( t )).…”