[gecode-users] Constraint graph available?

[Martin Mann]

Mikael 'Zayenz' Lagerkvist wrote:
> Hi,
> 
> In addition to Grégoire's comments, I would like to add the following.
> If you would extract a constraint graph from a Space, your example
> would not be binary, since you use a distinct-constraint. This mean
> that you would also have to transform the graph semantically to
> account for the fact that distinct represents a clique of not-equals,
> if you want a binary graph.

Thanks you are right. Thats why I would like to introduce 
non-propagating binary constraints, to transfor it internally into a 
binary constraint graph. This can be used to check the binary pathes in 
the graph without loosing the stronger propagation via the global 
constraint e.g. distinct.
Think that the reified constraints, Grégoire mentioned, will be usefull.

But never the less, this distinct/binary stuff is just something 
additional I m interested. The main focus is currently on real binary 
constraint graphs.


> However, there is one piece of information about the constraint-graph
> that is exposed. Using the degree()-member of an IntVar variable will
> return the number of constraints that subscribe to this variable. This
> is used for the variable selection strategies BVAR_DEGREE_MIN and
> BVAR_DEGREEE_MAX for branching on IntVar's.

Great, that sounds very usefull. I ve not found this selection 
strategies until now!
Thanks a lot!

Martin