Hi Christian, I had not even thought of the first option... the second option should be easily sufficient for our purposes. If it were possible to make that special case of "x == y" behave like "x IRT_EQ y" that would really benefit our use case. We have no interest in using DOM for the general case of "IntExpr1 == IntExpr2".
Many thanks for considering the idea, and the great software in general! Conrad Dr. Conrad Drescher Senior Developer | Variant Configuration P&I S/4HANA Idea - LoB Research & Development SAP SE | Dietmar-Hopp-Allee 16 | 69190 Walldorf | Germany T +49 6227 7-77888 | M +49 160 90684883 | E conrad.dresc...@sap.com www.sap.com<http://www.sap.com/> Please consider the impact on the environment before printing this e-mail. Pflichtangaben/Mandatory Disclosure Statements: http://www.sap.com/company/legal/impressum.epx Diese E-Mail kann Betriebs- oder Geschäftsgeheimnisse oder sonstige vertrauliche Informationen enthalten. Sollten Sie diese E-Mail irrtümlich erhalten haben, ist Ihnen eine Kenntnisnahme des Inhalts, eine Vervielfältigung oder Weitergabe der E-Mail ausdrücklich untersagt. Bitte benachrichtigen Sie uns und vernichten Sie die empfangene E-Mail. Vielen Dank. This e-mail may contain trade secrets or privileged, undisclosed, or otherwise confidential information. If you have received this e-mail in error, you are hereby notified that any review, copying, or distribution of it is strictly prohibited. Please inform us immediately and destroy the original transmittal. Thank you for your cooperation. From: Christian Schulte [mailto:cschu...@kth.se] Sent: Montag, 13. März 2017 09:41 To: Drescher, Conrad <conrad.dresc...@sap.com>; users@gecode.org Subject: RE: [gecode-users] Question on IntVar-equalities with and without MiniModel Hmmm, not that straightforward. There are two ideas here: - One idea would be that there is an additional IPL (integer propagation level) called something like IPL_CHEAP_DOM which does domain propagation only if it is cheap. - The other idea would be that linear interprets the default IPL ILP_DEF differently: normally it uses IPL_BND but for special cases it uses IPL_DOM. The second might be easier to pull off... Cheers Christian -- Christian Schulte, www.gecode.org/~schulte<http://www.gecode.org/~schulte> Professor of Computer Science, KTH, cschu...@kth.se<mailto:cschu...@kth.se> Expert Researcher, RISE ICT/SICS, cschu...@sics.se<mailto:cschu...@sics.se> From: users-boun...@gecode.org<mailto:users-boun...@gecode.org> [mailto:users-boun...@gecode.org] On Behalf Of Drescher, Conrad Sent: Friday, March 10, 2017 09:47 To: users@gecode.org<mailto:users@gecode.org> Subject: [gecode-users] Question on IntVar-equalities with and without MiniModel Hi there, I have a question on the "equal" constraint between two IntVars, let's say x0 with domain [1,3,5], and x1 with domain [Int::Limits::min..Int::Limits::max]. If I write rel(home,x0,IRT_EQ,x1); x1 gets restricted to [1,3,5] as IRT_EQs default propagation level is IPL_DOM. But if I write rel(home,x0 == x1); using MiniModel x1 gets restricted to [1 - 5]. Apparently equalities between linear integer expressions get summarized into a "linear" constraint in MiniModel, which of course is nice. This linear constraint in turn seems to have a lot of special cases covered (which I haven't fully grasped yet). But I wonder whether it'd be possible to get the case of there being just two variables back up to IPL_DOM instead of IPL_BND? Of course, I understand you wouldn't want to have IPL_DOM for linear in general... Many thanks! Conrad Dr. Conrad Drescher Senior Developer | Variant Configuration P&I S/4HANA Idea - LoB Research & Development SAP SE | Dietmar-Hopp-Allee 16 | 69190 Walldorf | Germany T +49 6227 7-77888 | M +49 160 90684883 | E conrad.dresc...@sap.com<mailto:conrad.dresc...@sap.com> www.sap.com<http://www.sap.com/> Please consider the impact on the environment before printing this e-mail. Pflichtangaben/Mandatory Disclosure Statements: http://www.sap.com/company/legal/impressum.epx Diese E-Mail kann Betriebs- oder Geschäftsgeheimnisse oder sonstige vertrauliche Informationen enthalten. Sollten Sie diese E-Mail irrtümlich erhalten haben, ist Ihnen eine Kenntnisnahme des Inhalts, eine Vervielfältigung oder Weitergabe der E-Mail ausdrücklich untersagt. Bitte benachrichtigen Sie uns und vernichten Sie die empfangene E-Mail. Vielen Dank. This e-mail may contain trade secrets or privileged, undisclosed, or otherwise confidential information. If you have received this e-mail in error, you are hereby notified that any review, copying, or distribution of it is strictly prohibited. Please inform us immediately and destroy the original transmittal. Thank you for your cooperation.
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