de.rwth.domains
Interface POSet

All Superinterfaces:

Set

All Known Subinterfaces:

CompleteLattice, CompletePOSet, Lattice, LowerSemiLattice, PreLattice, PreLowerSemiLattice, PreUpperSemiLattice, UpperSemiLattice

All Known Implementing Classes:

LiftedPOSet, FunctionPOSet, SumPOSet, StackPOSet, IntegerPOSet, TuplePOSet, TrivialPOSet, DualPOSet

public interface POSet

extends Set

Interface for partially ordered sets. Partially ordered sets have a binary less-than-or-equals relation le which must be reflexive, symmetric, and transitive. However, for two element a,b it can happen that they are incomparable, this is to say that le(a,b)=le(b,a)=false is allowed.

Version:

$Id: POSet.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

boolean	le(java.lang.Object e1, java.lang.Object e2) Checks if one element is less than or equal than an other element.
boolean	lt(java.lang.Object e1, java.lang.Object e2) Checks if one element is less than an other element.

Methods inherited from interface de.rwth.domains.Set

equals, isElement, iterator, iteratorSkel, size, sizeSkel

Method Detail

lt

public boolean lt(java.lang.Object e1,
                  java.lang.Object e2)

Checks if one element is less than an other element.

Implementations should guarantee that lt is reflexive, transitive and anti-symmetric. Furthermore, lt(e1,e2) should be the same as le(e1,e2)&&!equals(e1,e2).

Parameters:

e1 - a value of type Object

e2 - a value of type Object

Returns:

true iff both e1 and e2 are elements in this set and e1 is less or equals than /e2.

See Also:

Domain.checkProperties(POSet poset)

le

public boolean le(java.lang.Object e1,
                  java.lang.Object e2)

Checks if one element is less than or equal than an other element.

Implementations should guarantee that le is reflexive, transitive and symmetric. Furthermore, le(e1,e2) should be the same as lt(e1,e2)||equals(e1,e2).

Parameters:

e1 - a value of type Object

e2 - a value of type Object

Returns:

true iff both e1 and e2 are elements in this set and e1 is less than e2.

See Also:

Domain.checkProperties(POSet poset)