The ‘ phase velocity ’ of the system considered in this paper depends on the past of both the states (Oguztoreli, p. 184) and the controls (Banks and Jacobs, p. 464). However the results of Oguztöreli, Banks and Jacobs do not cover the dynamics of the plant considered in this paper. It is shown in this paper that by use of astronger topologyfor the class of measurable controls it is possible to prove theclosureof the set of trajectories (called the ‘ T-set ’) without requiring the ‘ velocity field ’ to be convex. This generalizes the class of systems at the expense of generality of the control class. In fact there is a trade-off between the two and one can be improved at the expense of the other.