de.rwth.domains
Interface UpperSemiLattice

All Superinterfaces:

POSet, PreUpperSemiLattice, Set

All Known Subinterfaces:

CompleteLattice, Lattice

public interface UpperSemiLattice

extends PreUpperSemiLattice

Interface for upper semi lattices. Upper semi lattices are partially ordered sets, where the least upper bound exists for any two elements.

Version:

$Id: UpperSemiLattice.java,v 1.2 2002/09/17 06:53:53 mohnen Exp $

Author:

Markus Mohnen

Inner classes inherited from class de.rwth.domains.Set

Set.Default

Method Summary

java.lang.Object

join(java.lang.Object e1, java.lang.Object e2) Computes the least upper bound of two elements.

Methods inherited from interface de.rwth.domains.POSet

le, lt

Methods inherited from interface de.rwth.domains.Set

equals, isElement, iterator, iteratorSkel, size, sizeSkel

Method Detail

join

public java.lang.Object join(java.lang.Object e1,
                             java.lang.Object e2)

Computes the least upper bound of two elements.
Implementations should guarantee that join is commutative and associative. Furthermore, join(e1,e2)=e2 iff le(e1,e2).

Specified by:

join in interface PreUpperSemiLattice

Parameters:

e1 - a value of type Object

e2 - a value of type Object

Returns:

the least upper bound of e1 and e2

See Also:

Domain.checkProperties(UpperSemiLattice usl)