本人小白一个，求大神看看问题所在

xiangbeihai

问题陈述：车辆路径问题，一个发点5个收点，中途可以转运，4种道路类型可供选择
model
sets:
!1发点5收点4种道路类型;
retailers/0,1,2,3,4,5,6/:cap,dem;
road/1,2,3,4/:p,a;
link(retailers,retailers,road)/: q,d,vel,x;
endsets
!目标函数;
submodel obj1:
min=z1;
z1=@sum(links:q*d);
endsubmodel
submodel obj2:
max=z2;
z2=@sum(links:vel*x);
endsubmodel
submodel obj3
min=z3;
z3=@sum(links:p*x);
endsubmodel
!需求约束;
@for(link(i,j,r):@sum(x(i,j,r))=1);!4;
@sum(link|i#ne#l:x(i,l,r))=@sum(link|j#ne#l:x(j,l,r));!5;
@for(link:DEM(l)=@sum(link|i#ne#l:Q(i,l,r))-@sum(link|j#ne#l:Q(j,l,r)));!6;
@sum(link(i,j,r):Q(i,j,r))>@sum(link(i,j,r):DEM(j)*x(i,j,r));!7;
@for(link:Q(i,j,r)<CAP*x(i,j,r)-DEM(i)*x(i,j,r));!8;
@for(link:VEL(i,j,r)<V(r)*x(i,j,r));!9;
Pr=VEL(i,j,r)*a(r);!10;
a1>a4>a2>a3;
Q(i,0,r)>0;
Q(i,j,r)>0;
Pr>0;
@bnd(0,x,1);
a(r)>0.005;
d(i,j,r)=@rand(seed)*50+10;
DEM(i)=@rand(seed)*1000+200;
VEL(i,j,r)=@rand(seed)*120+5;
data:
DEM(0)=0;
CAP=1000;
a(r)=0.25  0.1  0.05  0.15;
V(r)=30  55  80  120;
enddata
end