## Define restriction in a variable Topic is solved

Problems with modeling
Eduardo
User Posts: 2
Joined: 3 years ago

### Define restriction in a variable

Hello,
Could i put a restriction in a variable, depending the valor of the same variable?
I try to put:

Code: Select all

``````Binary Variable: x(i,k)
R(i,k)..    x(i,k)\$(x(i,k) eq 1) =g= x(i,k+1);``````
But this code doesn't work. How can i do something like before?
I want that if x(1,1)=1 =>x(1,2)=1 or 0 but if x(1,1)=0=> x(1,2)=1 or 0. (Because if a put x(i,k)=g=x(i,k+1) always x(1,1) will be 1 and i don't want.)

Best Regards

User Posts: 108
Joined: 3 years ago

### Re: Define restriction in a variable

Hola Eduardo.

What you are trying to accomplish is called disjunctive programming and is non trivial. Besides the theory to write that kind of constraints "on your own", there are some pre built solutions in GAMS. Checkout EMP:https://www.gams.com/latest/docs/usergu ... 1_2_3_0_13 and LogMIP: http://www.logmip.ceride.gov.ar/

Eduardo
User Posts: 2
Joined: 3 years ago