求助，为什么lingo总提示代码11的错误呢

自己写了一段代码，输了进去，结果总提示错误代码11，于是从《优化建模与lingo软件》这本书上找了一段代码，输了进去，还是提示同样的错误，而且我觉得提示的完全没有道理，是不是软件有问题啊？那位前辈给指点一下，谢啦~
代码如下：
model
sets:
needs/1..4/:length,num;
cuts/1..3/:x;
patterns(needs,cuts):r;
endsets
data:
length=4 5 6 8;
num=50 10 20 15;
capacity=19;
enddata
min=@sum(cuts(i):x(i));
@for(needs(i):@sum(cuts(j):x(j)*r(i,j)>num(i));
@for(cuts(j):@sum(needs(i):length(i)*r(i,j))<capacity);
@for(cuts(j):@sum(needs(i):length(i)*r(i,j))>capacity-@min(needs(i):length(i))+1);
@sum(cuts(i):x(i))>26; @sum(cuts(i):x(i))<31;
@for(cuts(i)|i#LT#@size(cuts):x(i)>x(i+1));
@for(cuts(j):@gin(x(j)));
@for(patterns(i,j):@gin(r(i,j)));
end