Binary variables in AMPL

[aaaa]

Hi everyone,

I need your help re defining binary variables in ampl. I have a mixed
integer programming problem with the objective function in minimizing
the makespan and the constraints include two binary variables as
follows:

Xi,j,q = 1, if the order i is assigned to the qth position
at stage j
0, otherwise

Yj,q,m = 1, if the order in the qth position is assigned to
machine m at stage j
0, otherwise

so, how should i define these in ampl, any idea?
any help regarding this will be appreciated.

[Paul]

set ORDER;
set STAGE;
set POSITION;
set MACHINE;
var X {i in ORDER, j in STAGE, q in POSITION} binary;
var Y {j in STAGE, q in POSITION, m in MACHINE} binary;

If you are asking how to write constraints that make the variables behave as you have indicated, that depends on the rest of your model.

Paul