Lingo里出现Model is ill defined

Lingo里出现Model is ill defined
!就是有A到J个任务,所需要的时间放在Time中,总共有4个相同机器,choose中放置所选机器编号（1~4）,问如何放置,总时间最短；
MODEL:
SETS:
TASK/ A B C D E F G H I J K/: Time,choose;
ENDSETS
DATA:
Time = 45 11 9 50 15 12 12 12 12 8 9;
ENDDATA
min=total;
@for(task(i)|i#le#4:@sum(task(j)|choose(j)#eq#i:Time)