# net1 is from AMPL's collection of examples (a network optimization problem
# with redundant active constraints)
# written in AMPL by Yu-Ju Kuo and Hans D. Mittelmann, 6/2001
param N;
param NH;
param NG;
param OG{1..N};
param UG{1..N}:=0;
param COST{1..N};
var X{1..N}:=10;
minimize obj: sum{i in 1..N}COST[i]*X[i];
s.t. hx1: 450.e0-X[1]-X[2]=0;
s.t. hx2: X[1]-X[3]-X[4]-X[5]=0;
s.t. hx3: X[2]-X[6]-X[7]-X[8]-X[9]=0;
s.t. hx4: X[3]-90.e0=0;
s.t. hx5: X[4]+X[6]-120.e0=0;
s.t. hx6: X[5]+X[7]-120.e0=0;
s.t. hx7: X[8]-70.e0=0;
s.t. hx8: X[9]-50.e0=0;
s.t. gxi{i in 1..9}: X[i]-UG[i]>=0;
s.t. gx2{i in 10..NG}: OG[i-9]-X[i-9]>=0;



data;
param N:=9;
param NH:=8;
param NG:=18;
param COST:=
1 2.5
2 2.5
3 1.7
4 0.7
5 1.3
6 1.3
7 0.8
8 0.2
9 2.1;
param OG:=
1 250
2 250
3 100
4 100
5 100
6 100
7 100
8 100
9 100;