有关lingo的一个错误程序

有关lingo的一个错误程序
model;
sets:
row/1,2,3,4/:b;
arrange/1,2,3,4,5/:x,p;
numb/1,2,3/:c;
link1(row,arrange):a1;
link2(numb,arrange):a2;
endsets
data:
p=16,13,15,20,20;
b=30,35,30,40;
c=20,25,20;
a1=7,1,3,5,2,3,4,4,2,5,3,2,3,5,3,2,5,6,3,5;
a2=1,2,3,1,2,2,2,1,3,1,2,1,2,1,2;
enddata
[ObJ]min=@sum(arrange(j):p(j)*x(j));
@for(row(i):@sum(arrange(j):a1(i,j)*x(j))>=b(i););
@for(numb(i):@sum(arrange(j):a2(i,j)*x(j))