20 points In the two-level discrete multi-facility model, given below, what is the purpose of the starred constraint? That is, tell me in words why the constraint exists. Minz=i=1mFiyi+i=1mj=1ncijxij+k=1zQkak+k=1zi=1mtkifkis.t.i=1mxijdjj=1,,nj=1nxijCAPiyii=1,,mj=1nxijk=1zfkii=1,mi=1mf,kiPCkakk=1,,zxij0i=1,,m,j=1,,nyi={0,1}i=1,,mak={0,1}k=1,,zfki0k=1,,z,i=1,,m 20 points In the two-level discrete multi-facility model, given below, what is the purpose of the starred constraint? That is, tell me in words why the constraint exists. Minz=i=1mFiyi+i=1mj=1ncijxij+k=1zQkak+k=1zi=1mtkifkis.t.i=1mxijdjj=1,,nj=1nxijCAPiyii=1,,mj=1nxijk=1zfkii=1,mi=1mf,kiPCkakk=1,,zxij0i=1,,m,j=1,,nyi={0,1}i=1,,mak={0,1}k=1,,zfki0k=1,,z,i=1,,m