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Hi Liding and Marc,</div>
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Thanks for your help, that all makes sense. I was worried I was getting 'extra' cuts from strong branching, so it's good to know that is not the case.</div>
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James</div>
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James Cussens</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Xu, Liding <liding.xu@zib.de><br>
<b>Sent:</b> 05 March 2025 12:18<br>
<b>To:</b> James Cussens <james.cussens@bristol.ac.uk>; scip@zib.de <scip@zib.de><br>
<b>Subject:</b> Re: strong branching and cuts</font>
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<p>Hi James,</p>
<p> In addition to Marc's reply, propagations are applied to sub-LPs during strong branching, which essentially add simple variable-bound change cuts. For more details, you may find the function performStrongbranchWithPropagation().</p>
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<p>Best</p>
<p>Liding</p>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Scip <scip-bounces@zib.de> on behalf of James Cussens <james.cussens@bristol.ac.uk><br>
<b>Sent:</b> Wednesday, March 5, 2025 12:24:32 PM<br>
<b>To:</b> scip@zib.de<br>
<b>Subject:</b> [SCIP] strong branching and cuts</font>
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As I understand it, when running strong branching on a candidate branching variable, the 'down-branch' and 'up-branch' LPs are solved and we can inspect the associated dual bounds to measure how good a choice the candidate would be to branch on.</div>
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I can't work out whether cuts are added to these two LPs and, if so, how to prevent them being added. Could someone enlighten me?</div>
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Evidently, if the down and up LPs undergo some separation rounds then we get more useful dual bounds and thus a better idea of the quality of the variable as something to branch on. However, if those separation rounds are expensive, it might be better to skip
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Phone: +44 (0)117 455 8723</div>
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