lingo程序哪里出错了 怎么改啊

lingo程序哪里出错了 怎么改啊
想让s为0-1变量 在v(I,J)不为0的时候,s为1.完全新手,
sets:
supplyment/s1..s20/:supply;
receiver/r1..r20/:demand;
links(supplyment,receiver ):cost,v,s;
endsets
min=@sum(links:cost*s);
@for(receiver(J):
@sum(supplyment(I):v(I,J))=demand(J));
@for(supplyment(I):
@sum(receiver(J):v(I,J))