“…(8), (9), and (10) and fu (x\n,u,d) into Eqs. (8), (9), and (14) we obtain two sets of five macroscopic equations of motion governing, in the first case, n, u, and 5, and in the second, n, u and 6. These equations determine the development of the macroscopic variables in such a way that, if n(q), u(q) y d(q) 1 and n(q), xi(q) and 8(q) are equivalent states at t~ 0, they are equivalent for all times.…”