Originally posted by: stef44

Hi all, 

I am interested in pruning nodes of the search tree during my propagation (filtering rules) implemented in a global constraint. What is the most 'efficient' way to do that?

E.q. Lets say I found a value/state which I know its infeasible and will be for the rest for that part of the tree. How do I 'prune' the node then? I would like in the next step of the constraint propagation, the search not to investigate that part of the tree.

Any answer would be appreciated, thank you!

Originally posted by: PhilippeLaborie

Then you probably want to remove the infeasible value from the domain of the variable by doing something like IlcIntVar::removeValue(val). This will remove 'val' from the domain of the variable in a reversible way.

If the propagation of the constraint detects that the current state/node is infeasible and thus that there is no feasible solution under this node, you can call IlcConstraintI::fail(), this will tell the search to backtrack.

Philippe