[gecode-users] Constraint graph available?

[Mikael 'Zayenz' Lagerkvist]

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.

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.

Cheers
Mikael

On 5/11/06, Martin Mann <mmann at informatik.uni-freiburg.de> wrote:
>
> I would like to use the structure of the constraint graph in my search
> strategy.
> The constraint graph will be binary and the whole CSP will be formulated
> with binary constraints.
>
> Is it possible to get a list of all NOT entailed constraints of a
> Gecode::Space? Or an other way to access this data without managing and
> updating an additional contraint graph in the space via adjacency list etc?
>
>
>
> In addition I would like to know if it's possible to insert a contraint
> X and hinder X to propagate. The propagation should be done by
> constraint Y and X only used to test if X is entailed or not. For example:
> 3 vars A,B,C
> 1 distinct (ABC) with ICL_DOM for full propagation
> 2 neq constraints (AB) (BC)
>
> (AB) and (BC) are included in (ABC), so they dont have to propagate.
> i want to use (AB) and (BC) to test if this variables are not equal or not.
> Or can I ask the global constraint (ABC) directly?
>
> Seems to be my week of questions.. ;)
> Hope you dont get bored!
>
> Thanks for answers
>
> Martin
>
>
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-- 
Mikael 'Zayenz' Lagerkvist, http://www.ict.kth.se/~zayenz/