. , pin } does not infect the feasibility of pij . lemma 2 . 3 there exists an optimal schedule with the form ( a , r ) , where all jobs in a can meet their due - dates and satisfies 其中a是所有按时完工的工件组成的集合, r是所有延误的工件组成的集合,并且a中的元素满足攻王久三? ? ,三d勺; 11s2s …三l厂由引理2