这个lingo语句的错误在哪里?
MODEL:
SETS:
WH/W1..W6/:AI;
VD/V1..V8/:DJ;
LINKS(WH,VD):C,X;
ENDSETS
DATA:
AI=60,55,51,43,41,52;
DJ=35,37,22,32,41,32,43,38;
C=6,2,6,7,2,5,9
4,9,5,3,8,5,8,2
5,2,1,9,7,4,3,3
7,6,7,3,9,2,7,1
2,3,9,5,7,2,6,5
5,5,2,2,8,1,4,3;
ENDDATA
MIN=@SUM(LINKS(I,J):C(I'J)*X(I,J));
@FOR(WH(I):@SUM(VD(J):X(I,J))