Hi Bauke, Damn it, you are of course right. I just fixed it in the trunk.
Thanks! Christian -- Christian Schulte, Professor of Computer Science, KTH, www.ict.kth.se/~cschulte/ -----Original Message----- From: Bauke Conijn [mailto:b.j.con...@student.tue.nl] Sent: Tuesday, February 18, 2014 7:51 PM To: cschu...@kth.se; users@gecode.org Subject: Re: [gecode-users] Unary constraint not-first-not-last propagation does not cancel optional tasks Hi Christian, I know that optional tasks cannot have their start and end times pruned, however, their mandatory flag can be marked false. It seems that the two commented-out lines would discard the optional tasks when it detects that they cannot be mandatory. Very similar code can be found in detectable.hpp: for (int i=n; i--; ) if (t[i].mandatory()) { GECODE_ME_CHECK(t[i].est(home,est[i])); } else if (est[i] > t[i].lst()) { GECODE_ME_CHECK(t[i].excluded(home)); t[i].cancel(home,p,Int::PC_INT_BND); t[i]=t[--n]; } Kind regards, Bauke On 02/17/2014 03:59 PM, Christian Schulte wrote: > Hi Bauke, > > No, they can't, in the current setup this would make the propagator > incorrect. The reasoning is as follows: while the task is still > optional, one is not allowed to prune anything. The reason why the > code still lingers on as a comment is that if one introduces an > additional wrapper in forms of task variables, this kind of reasoing could be used. > > Best > Christian > > -- > Christian Schulte, Professor of Computer Science, KTH, > www.ict.kth.se/~cschulte/ > > > -----Original Message----- > From: users-boun...@gecode.org [mailto:users-boun...@gecode.org] On > Behalf Of Conijn, B.J. > Sent: Friday, February 14, 2014 2:08 PM > To: users@gecode.org > Subject: [gecode-users] Unary constraint not-first-not-last > propagation does not cancel optional tasks > > Hi, > > In not-first-not-last.hpp I found the following piece of code and I > was wondering why those two lines have been commented out. While > running the tests with those two lines included, those lines get > executed and the test still succeeds. Can those two lines be safely included? > > if (t[i].mandatory()) { > GECODE_ME_CHECK(t[i].lct(home,lct[i])); > } else if (lct[i] < t[i].ect()) { > // GECODE_ME_CHECK(t[i].excluded(home)); > // t[i].cancel(home,p); t[i]=t[--n]; > } > > Kind regards, > > Bauke > > _______________________________________________ > Gecode users mailing list > users@gecode.org > https://www.gecode.org/mailman/listinfo/gecode-users > _______________________________________________ Gecode users mailing list users@gecode.org https://www.gecode.org/mailman/listinfo/gecode-users
