15.5 Disjunctive Propagators

There are several ways in Oz to express disjunctive information. Disjunctive information can be written into the constraint store by using finite domain membership constraints such as X :: 1#5. Another conveniant way is to use disjunctive propagators which can be written is Oz by or-statements.

As we will see, both forms of disjunctive inteformation can be interlocked in an useful manner.

• 15.5.1 or-Statements

• 15.5.2 Operational Semantics

• 15.5.3 Propositional Logic

• 15.5.4 Choice Points versus Choice Variables