model:
sets:
cities/1..11/;
roads(cities,cities):w,x;
endsets
data:
w=0;
enddata
calc:
w(1,2)=2;w(1,3)=8;w(1,4)=1;
w(2,3)=6;w(2,5)=1;
w(3,4)=7;w(3,5)=5;w(3,6)=1;w(3,7)=2;
w(4,7)=9;
w(5,6)=3;w(5,8)=2;w（5,9）=9；
w(6,9)=6;
w(7,9)=3;w(7,10)=1;
w(8,9)=7;w(8,11)=9;
w(9,10)=1;w(9,11)=2;
w(10,11)=4;
@for(roads(i,j):w(i,j)=w(i,j)+w(j,i));
@for(roads(i,j):w(i,j)=@if(w(i,j) #eq# 0, 1000,w(i,j)));
endcalc
n=@size(cities);  
min=@sum(roads:w*x);
@for(cities(i)|i #ne#1 #and# i #ne#
n:@sum(cities(j):x(i,j))=@sum(cities(j):x(j,i)));
@sum(cities(j):x(1,j))=1;
@sum(cities(j):x(j,1))=0;
@sum(cities(j):x(j,n))=1;
@for(roads:@bin(x));
end
运行出现improper use of attribute name
14] w(5,6)=3;w(5,8)=2;w(5,9)=9;这个是怎么回事