[gecode-users] LDSB : value symmetry on subset of branching variables ?

[Martin Mann]

Hi Gecoders,

a question concerning LDSB search breaking value symmetry.

I have a CSP where the branching is done on a set of variables X = X_1 + 
X_2 composed from two other sets X_1 and X_2.

I have different value symmetries for X_1 and X_2 that I want to impose.

As far as I see, I can only post the symmtries for a "full" branching.

Thus, if I want to enforce different symmetry breakings for X_1 and X_2, 
I have to split my branching into two successive branchings right? If 
so, this might weaken the search compared to branching on whole X (which 
is hopefully compensated by the symmetry breaking).

Or is there another way around it to specify for which variables what 
symmetry object is to be applied?

Thanks for advice,
Martin

-- 
Dr. Martin Mann, Postdoc
Bioinformatics - Inst. of Computer Science
Albert-Ludwigs-University Freiburg
Tel: ++49-761-203-8254
Fax: ++49-761-203-7462
http://www.bioinf.uni-freiburg.de/~mmann/