this my code, it is too long, so, I hope that you can understand it :

```
scheduling=MixedIntegerLinearProgram(maximization=false )
from sage.numerical.mip import Sum
#####variables
f = scheduling.new_variable (dim=4, binary=true)
#f is the source to destination in time t
l = scheduling.new_variable (dim=4, binary=true)
#L id 0 if link op not selected for demand k in time t
A = scheduling.new_variable(dim=6,binary=true)
# A is binary s to d in link op in time t for demand k
z_op=scheduling.new_variable(dim=2,binary=true)
#Z is 1 if is link op is on
y = scheduling.new_variable(dim=1,binary=true)
#####parameters
Num_demand_slice= 1
#number of the time slice
power_link_op= matrix ([[1,1,1,1,1],[1,1,1,1,1],[1,1,1,1,1],[1,1,1,1,1],[1,1,1,1,1]])
# power of the link op that is considered as cost
demand_traffic_kt = matrix ([1]);
# 0/1 matrix if demand has traffic in t is 1
rate_k= [2];
#rate of the trafic of the demand k
link_capacity_op= matrix ([[0,0,30,30,30],[0,0,30,30,30],[30,30,0,0,0],[30,30,0,0,0],[30,30,0,0,0]])
# zero if not exist this link in graph, others capacity of that 5 or 6 (not binary matrix)
power_sw_o= [[0,0,2,2,2]]
#power of the sw o if is zero means that it is server
V=5
K=1
B=Num_demand_slice * K
#####constraint
# v is the num of the node
# K is the num of the node
for o in range (0,V):
for p in range (0,V):
if (link_capacity_op[o][p]==0):
for t in range (0,Num_demand_slice):
for k in range (0,K):
scheduling.add_constraint(l[o][p][k][t]==0)
for t in range (0,Num_demand_slice ):
for k in range (0,K):
if demand_traffic_kt[k][t]==0 :
for s in range (0,V ):
for d in range (0,V ):
scheduling.add_constraint(f[s][d][k][t]==0)
for t in range (0,Num_demand_slice ):
for k in range (0,K):
if demand_traffic_kt[k][t]==0 :
for o in range (0,V ):
for p in range (0,V ):
scheduling.add_constraint(l[o][p][k][t]==0)
for t in range(0,Num_demand_slice):
for d in range(0,V ):
for k in range(0,K ):
for o in range(0,V ):
for p in range(0,V ):
for s in range(0,Num_demand_slice ):
scheduling.add_constraint(f[s][d][k][t] + l[o][p][k][t]- 1 <= A[s][d][k][o][p][t])
for t in range(0,Num_demand_slice ):
for d in range(0,V ):
for k in range(0,K ):
for o in range(0,V ):
for p in range(0,V ):
for s in range(1,Num_demand_slice+1 ):
scheduling.add_constraint(f[s][d][k][t] + l[o][p][k][t] >= 2* A[s][d][k][o][p][t])
for t in range(0,Num_demand_slice ):
for k in range(0,K):
for ...
```

(more)
It's usually not possible to debug a program without seeing it. If you can edit your question and add a minimal example the recreates your problem then someone can try to help.