Yep, it means just scheduling. Propagation is always explicit in Gecode, triggered by status().
Christian -- Christian Schulte, web.ict.kth.se/~cschulte/ -----Original Message----- From: Kish Shen [mailto:[email protected]] Sent: Friday, July 16, 2010 7:40 PM To: [email protected] Cc: [email protected] Subject: Re: [gecode-users] posting instead of propagating domain constraints? Christian Schulte wrote: > Well, dom() and the integer variants of rel() propagate in the sense that > they immediately modify the variable domain and schedule some propagators > for later execution. However, they do not lead to full constraint > propagation computing a fixpoint. The invariant is that only execution of > the status() function of a space computes a fixpoint. So they are dirt > cheap, much cheaper than creating a propagator for them. Yes, I had understood 'propagates' in the manual to mean 'full propagation'. I knew that dom() and rel() will do such simple things like update the domain and check that the value you are assigning is inside the domain, etc., and assumed that you will always do these simple checks for all constraints posted, even where the manual says 'posting the propagator', e.g. for equality between two IntVars, you will check that their domains do overlap, etc. So does 'propagate' in this case only mean 'scheduling some propagators', whereas where the manual state 'posting the propagator' does not? Cheers, Kish -- This e-mail may contain confidential and privileged material for the sole use of the intended recipient. Any review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient (or authorized to receive for the recipient), please contact the sender by reply e-mail and delete all copies of this message. Cisco Systems Limited (Company Number: 02558939), is registered in England and Wales with its registered office at 1 Callaghan Square, Cardiff, South Glamorgan CF10 5BT. _______________________________________________ Gecode users mailing list [email protected] https://www.gecode.org/mailman/listinfo/gecode-users
