Make sure the limits of the Tree/ADD potential match those of the variable's domain

[Iñigo Bermejo]

Make sure the limits of the Tree/ADD potential match those of the top variable's domain.

[Iñigo Bermejo]

Reproduction steps:

• Create node A and make it numeric.
• Create node B and draw a link from node A to node B
• Edit node B's potential. Make it a Tree/ADD. It have a single leaf by default, including the whole range of A's domain (by default (-infinity, +infinity)).
• Reduce node A's domain to [0,+infinity).
• Go back to B's potential and see that the Tree/ADD's leaf range has not changed.

[Manuel Luque]

The implementation should be made very carefully, as the reduction of the domain could even make some TreeADD interval disappear. For example, let us suppose that a TreeADD have three intervals: (-infinity, -1), [-1,1] and (1,infinity), and then the user decides to reduce the domain to (0,infinity).

[Francisco Javier Díez]

Certainly, in some cases when the domain changes some branches should be pruned. In contrast, increasing the upper limit of the domain should lead to an increase of the upper limit of the corresponding branch instead of adding a new branch.