在lingo最优化程序中,总说模型定义错误,还有15号错误,这是怎么回事,要怎么改,想了很久也没想出哪错

在lingo最优化程序中,总说模型定义错误,还有15号错误,这是怎么回事,要怎么改,想了很久也没想出哪错
model:
sets:
head/1..10/:;
tail/1..10/:;
links(head,tail):q,w;
endsets
data:
w=0 0.8 0.5 0.9 1.2 1.4 1.2 1.6 1.7 2.2
0.8 0 0.9 1.5 1.7 0.8 1.1 1.8 1.4 2.2
0.5 0.9 0 0.7 0.9 1.1 0.7 1.2 1.2 1.7
0.9 1.5 0.7 0 0.3 1.7 1 0.7 1.5 1.8
1.2 1.7 0.9 0.3 0 1.8 1 0.6 1.5 1.5
1.4 0.8 1.1 1.7 1.8 0 0.9 1.4 0.8 1.6
1.2 1.1 1.2 0.7 1 1 0 0.8 0.6 1.1
1.6 1.8 1.2 0.7 0.6 1.4 0.8 0 1.1 1.1
1.7 1.4 1.2 1.5 1.5 0.8 0.6 1.1 0 1
2.2 2.2 1.7 1.8 1.5 1.6 1.1 1.1 1 0;
enddata
min=@sum(links(i,j):0.66*q(i,j)^0.5*w(i,j));
@sum(head(i):q(i,1))=0;
@sum(tail(j):q(i,2))>=50+@sum(tail(j):q(2,j));
@sum(tail(j):q(i,3))>=80+@sum(tail(j):q(3,j));
@sum(tail(j):q(i,4))>=60+@sum(tail(j):q(4,j));
@sum(tail(j):q(i,5))>=40+@sum(tail(j):q(5,j));
@sum(tail(j):q(i,6))>=85+@sum(tail(j):q(6,j));
@sum(tail(j):q(i,7))>=65+@sum(tail(j):q(7,j));
@sum(tail(j):q(i,8))>=55+@sum(tail(j):q(8,j));
@sum(tail(j):q(i,9))>=45+@sum(tail(j):q(9,j));
@sum(tail(j):q(i,10))>=95+@sum(tail(j):q(10,j));
@sum(tail(j):q(1,j))>=575;
@for(links(i,j):@if(i#ge#j,0,q(i,j)));
end
结果显示：
No relational operator found.
31] @for(links(i,j):@if(i#ge#j,0,q(i,j)));
^
到底是哪里有问题