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Re: [Help-glpk] 'not' or 'or' constraints?

 From: François Galea Subject: Re: [Help-glpk] 'not' or 'or' constraints? Date: Fri, 27 May 2005 10:46:53 +0200 User-agent: Mozilla Thunderbird 1.0.2 (X11/20050331)

```Philip,

such 'or' constraints mean that your problem is neither a LP or a MIP.

```
In fact, if you have a single 'or' constraint, you can solve two independent problems, the first one with the first OR condition only, and the second with the second OR condition only. The optimal solution is the best of the optimal solutions in both problems.
```
```
Then, solving problems with a bigger amount of 'or' conditions would result in solving 2^n different problems, n being the number of 'or' conditions you have.
```
François

Philip Warner a écrit :
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```
```
This may not be the right forum for this, but I need to solve an LP problem that is subject to constraints like:
```
s <= 0 OR s >= 100

or, rewritten,

Not (0 < s < 100)

Is this something I can do in GLPK?

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```
```

--
François Galea
Laboratoire PRiSM
Université de Versailles-Saint Quentin en Yvelines
45 av Etats-Unis F-78035 Versailles CEDEX
Tél. : +33 1 39 25 40 50

```