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1.5  User-Defined Constraints

1.5.1  Generalised Propagation: propia

The predicate infers takes as one argument any user-defined predicate, and as a second argument a form of propagation to be applied to that predicate.

This functionality enables the user to turn any predicate into a constraint [16]. The forms of propagation include finite domains and intervals.

1.5.2  Constraint Handling Rules

The user can also specify predicates using rules with guards [9]. They delay until the guard is entailed or disentailed, and then execute or terminate accordingly.

This functionality enables the user to implement constraints in a way that is clearer than directly using the underlying suspend library.

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