关于lingo的问题 老是出错！求帮忙！

sets:

si/1..4/:s;

sj/1..5/:f,y,b,m;

sk/1..8/:demand,t;

lij(si,sj):x,d;

ljk(sj,sk):d2,x2;

endsets

min=@sum(sj(j):f(j)*y(j))+@sum(lij(i,j):b(j)*x(i,j)*y(j))+p*(@sum(lij(i,j):d(i,j)*spoil*y(j))+@sum(ljk(j,k):d2(j