Idea: variables whose constraints have been eliminated should not actively be solved

[pvdz]

This is confusing but it means that if you add lt(A, B) and the constraint is eliminated because all elements in A are already lower than those in B, A and B should not be solved explicitly in the search. They should still be solved, but only when a solution is constructed should these vars be solved to any value that is still left in the domain. Probably would need to apply the value distributor for every such var.

The main point is that the search should not create new spaces just so it can solve those variables whose constraints have been eliminated at compile time. External code may depend on an actual solution, but that doesn't mean that the search should be burdened with them because it doesn't need to. When variables have no constraints, any value in their domain is considered a valid outcome.

• This should be fairly trivial change to make