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<div class="moz-cite-prefix">James,<br>
<br>
Does not look feasible to me<br>
<br>
SOS says at most one of neg and lt can be non-zero - not that at
most one can be positive (It would not surprise me if there were
bugs with negative members of SOS). That solution has both
non-zero. I presume you have simplified example to give to us.
You could try using "pos" instead or if daring derive a
specialized version of SOS.<br>
<br>
John<br>
<br>
On 06/03/18 20:04, James Howey wrote:<br>
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<p class="MsoNormal">The following is an effort to set a binary
indicator (lt) if x <= 44000<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">maximize<o:p></o:p></p>
<p class="MsoNormal">lt<o:p></o:p></p>
<p class="MsoNormal">SUBJECT TO<o:p></o:p></p>
<p class="MsoNormal">x - ff - neg = 0<o:p></o:p></p>
<p class="MsoNormal">44000 lt + neg >= 0<o:p></o:p></p>
<p class="MsoNormal">BOUNDS<o:p></o:p></p>
<p class="MsoNormal">x = 1<o:p></o:p></p>
<p class="MsoNormal">ff = 44000<o:p></o:p></p>
<p class="MsoNormal">-44000 <= neg <= 1e15<o:p></o:p></p>
<p class="MsoNormal">binary<o:p></o:p></p>
<p class="MsoNormal">lt<o:p></o:p></p>
<p class="MsoNormal">SOS<o:p></o:p></p>
<p class="MsoNormal">set1: S1:: neg:0 lt:1<o:p></o:p></p>
<p class="MsoNormal">END<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">With command arguments <o:p></o:p></p>
<p class="MsoNormal" style="text-indent:.5in">preprocess off
solve solu a<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The result reached is:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Integer infeasible - objective value
-1.00000000<o:p></o:p></p>
<p class="MsoNormal"> 0 lt
1 -1<o:p></o:p></p>
<p class="MsoNormal"> 1 x
1 0<o:p></o:p></p>
<p class="MsoNormal"> 2 ff
44000 0<o:p></o:p></p>
<p class="MsoNormal"> 3 neg
-43999 0<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Which appears feasible to me?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any insight is appreciated.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">jkh<o:p></o:p></p>
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