Class AleB

  • All Implemented Interfaces:
    SatisfiedPresent, StoreAware

    public class AleB
    extends PrimitiveConstraint
    It creates a <= b constraint on two set variables. The set variables are constrained to be lexicographically ordered.

    For example, {}<=lex {} {}<=lex {1} {1, 2}<=lex {1, 2} {1, 3}<=lex {2} {1}<= {2}

    Version:
    4.7
    • Field Detail

      • idNumber

        static java.util.concurrent.atomic.AtomicInteger idNumber
      • a

        public SetVar a
        It specifies the first variable of the constraint
      • b

        public SetVar b
        It specifies the second variable of the constraint
      • aGTb

        AltB aGTb
        Negated constraint
    • Constructor Detail

      • AleB

        public AleB​(SetVar a,
                    SetVar b)
        It constructs an Lexical ordering constraint to restrict the domain of the variables a and b.
        Parameters:
        a - variable that is restricted to be less than b with lexical order.
        b - variable that is restricted to be greater than a with lexical order.
      • AleB

        AleB​(SetVar a,
             SetVar b,
             boolean negated)
        It constructs an Lexical ordering to be used in negated constrained. Not to be used for imposing constraints.
        Parameters:
        a - variable that is restricted to be less than b with lexical order.
        b - variable that is restricted to be greater than a with lexical order.
        negated - used to distinguish constructors only.
    • Method Detail

      • consistency

        public void consistency​(Store store)
        Description copied from class: Constraint
        It is a (most probably incomplete) consistency function which removes the values from variables domains. Only values which do not have any support in a solution space are removed.
        Specified by:
        consistency in class Constraint
        Parameters:
        store - constraint store within which the constraint consistency is being checked.
      • notConsistency

        public void notConsistency​(Store store)
        Description copied from class: PrimitiveConstraint
        It makes pruning in such a way that constraint is notConsistent. It removes values which always belong to a solution.
        Specified by:
        notConsistency in class PrimitiveConstraint
        Parameters:
        store - the constraint store in which context the notConsistency technique is evaluated.
      • satisfied

        public boolean satisfied()
        Description copied from interface: SatisfiedPresent
        It checks if the constraint is satisfied. It can return false even if constraint is satisfied but not all variables in its scope are grounded. It needs to return true if all variables in its scope are grounded and constraint is satisfied.

        Implementations of this interface for constraints that are not PrimitiveConstraint may require constraint imposition and consistency check as a requirement to work correctly.

        Returns:
        true if constraint is possible to verify that it is satisfied.
      • notSatisfied

        public boolean notSatisfied()
        Description copied from class: PrimitiveConstraint
        It checks if constraint would be always not satisfied.
        Specified by:
        notSatisfied in class PrimitiveConstraint
        Returns:
        true if constraint must be notSatisfied, false otherwise.
      • impose

        public void impose​(Store store)
        Description copied from class: Constraint
        It imposes the constraint in a given store.
        Overrides:
        impose in class PrimitiveConstraint
        Parameters:
        store - the constraint store to which the constraint is imposed to.
      • toString

        public java.lang.String toString()
        Description copied from class: Constraint
        It produces a string representation of a constraint state.
        Overrides:
        toString in class Constraint