Consider a scheduling model in which a machine can be switched on at most k times during a horizon of T periods. In this model, there are two sets of variables: y = 1 if the machine is on during period t, and z = 1 if the machine is switched on in period t. Then the constraints look like the following: FAT k t=1 2tyt+Yt-120, Vt = 1,...,T 2tyt, Vt = 1,...,T Yt, t (0,1}, Vt = 1,...,T where yo is taken to be zero in the second set of constraints. Show that the constraint matrix is TU.