“…which is of the form jg T (z)j( )jg(z)j 0 or equivalently jg T (z)j jg(z)j 0: On the other hand, if is a positive de…nite matrix, then, for all g(z(t)) 6 = 0, we have jg T (z)j jg(z)j > 0: Obviously, when > 0, (14) contradicts with (15), implying that under the condition of Theorem 1, the equilibrium equation of system (5) given by (6) cannot have a solution where g(z) 6 = 0. Thus, we can conclude that Theorem 1 guarantees that the origin of system (5) is the unique equilibrium point.…”