On the properties of combination set operations

The problem of constructing a combination set to represent a collection of all solutions by solving constraint satisfaction problems is considered. Two kinds of combination set operations, restriction and exclusion, are invented. Simplification theorems on these two operations plays an important role to avoid combinatorial explosions. In addition, a zero-suppressed BDD, a variation of ordered binary decision diagrams, is adopted to represent a combination set and efficient implementations of the two operations are presented.