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# Binary variable in mixed integer linear program

asked 2015-09-28 08:58:51 +0200

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Hi asksage!

I'm using the MixedIntegerLinearProgram class to model a mixed integer linear program. I am using binary variables created e.g. by x = mip.new_variable(binary=True, name="x"). Now, I am using this variable e.g. by x[0] or x[3,2]. When I create a constraint using sums over binary variables, this sum is in the integers, as it should be. However, I am wondering if there is another way to easily add such variables together over GF(2) such that e.g. x[0] + x[0] disappears from the equation?

I ask because my model is too complicated to write by hand, so I am using some auxiliary methods to construct constraints and variables, etc.

I hope you can help me out!

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## 1 Answer

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No sorry, I do not think that any of the solvers we use support that.

Did you think of modelling your problem as a SAT problem instead? Could it help? Obviously it may not be possible depending on what you want to solve, but it may also be easier with this other formalism.

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## Comments

Hi Nathann, thanks for your quick reply. That is unfortunately. Alternatively, if only I could find a way that I can make a list of binary symbolic variables x[0] , ..., x[n-1] that I can work with over GF(2), this would give me something to go from. While this is somewhat unrelated, would you know how to accomplish this?

( 2015-09-28 09:34:05 +0200 )edit

I do not know, but you should ask on sage-support. Other will know better than I, and they may not read this thread.

( 2015-09-28 20:20:06 +0200 )edit

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Asked: 2015-09-28 08:58:51 +0200

Seen: 222 times

Last updated: Sep 28 '15