revisionlogic
Class Tautology

java.lang.Object
  revisionlogic.ISent
      revisionlogic.Tautology

final class Tautology

extends ISent

Tautology represents a tautology. It is a concrete subclass of ISent.

Author:

Daphne Liu, daphnel@sfu.ca

Field Summary

Fields inherited from class revisionlogic.ISent

ATOM, BIIMP, CONJ, CONT, DIS, IMP, NEG, TAUT

Constructor Summary

(package private)

Tautology()

Method Summary

java.lang.Object	clone() Returns a reference to this Tautology.
(package private) ISent	conjunctionsIn() Returns a reference to this Tautology, as the dnf transformation of a tautology T remains the same as the tautology.
(package private) ISent	disjunctionsIn() Returns a reference to this Tautology, as the cnf transformation of a tautology T remains the same as the tautology.
boolean	equals(java.lang.Object s) Checks if this Tautology equals s.
(package private) java.util.HashSet	getAtoms() Returns the empty set of literals of this Tautology.
ISent	getCNF() Returns a reference to this Tautology, as the cnf transformation of a tautology T remains the same as the tautology.
ISent	getCNFUI() Returns a reference to this Tautology, as the cnf transformation of a tautology T remains the same as the tautology.
(package private) int	getDepth() Returns the depth of this Tautology.
ISent	getDNFUI() Returns a reference to this Tautology, as the dnf transformation of a tautology T remains the same as the tautology.
java.lang.String	getLabel() Returns the string representation of this Tautology.
(package private) java.lang.StringBuffer	getLabelSB() Returns null as this method is never invoked on this Tautology but implemented only to satisfy the abstract specification of ISent.
int	getType() Returns the type of this Tautology.
(package private) ISent	implicationsOut() Returns a reference to this Tautology, as the cnf and dnf transformations of a tautology T remain the same as the tautology.
boolean	isConsistent() Returns true to indicate this Tautology is itself consistent.
(package private) ISent	negationsIn() Returns a reference to this Tautology, as the cnf and dnf transformations of a tautology T remain the same as the tautology.

Methods inherited from class revisionlogic.ISent

getDIMACSFormat, isConsistent, isConsistent, isInconsistentSList, isprConsistent

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Tautology

Tautology()

Method Detail

clone

public java.lang.Object clone()

Returns a reference to this Tautology.

This shallow cloning is acceptable since the cnf and dnf transformations of a tautology T remain the same as the tautology.

Specified by:

clone in class ISent

Returns:

a reference to this Tautology.

equals

public boolean equals(java.lang.Object s)

Checks if this Tautology equals s.

Specified by:

equals in class ISent

Returns:

true if s is a Tautology, false otherwise.

getDepth

int getDepth()

Returns the depth of this Tautology.

Specified by:

getDepth in class ISent

Returns:

always 0 for the depth of this Tautology.

getType

public int getType()

Returns the type of this Tautology.

Specified by:

getType in class ISent

Returns:

an int indicating the tautological type.

isConsistent

public boolean isConsistent()

Returns true to indicate this Tautology is itself consistent.

Overrides:

isConsistent in class ISent

Returns:

always true to indicate this Tautology is itself consistent.

implicationsOut

ISent implicationsOut()

Returns a reference to this Tautology, as the cnf and dnf transformations of a tautology T remain the same as the tautology.

Specified by:

implicationsOut in class ISent

Returns:

a reference to this Tautology.

negationsIn

ISent negationsIn()

Returns a reference to this Tautology, as the cnf and dnf transformations of a tautology T remain the same as the tautology.

Specified by:

negationsIn in class ISent

Returns:

a reference to this Tautology.

disjunctionsIn

ISent disjunctionsIn()

Returns a reference to this Tautology, as the cnf transformation of a tautology T remains the same as the tautology.

Specified by:

disjunctionsIn in class ISent

Returns:

a reference to this Tautology.

conjunctionsIn

ISent conjunctionsIn()

Returns a reference to this Tautology, as the dnf transformation of a tautology T remains the same as the tautology.

Specified by:

conjunctionsIn in class ISent

Returns:

a reference to this Tautology.

getCNF

public ISent getCNF()

Returns a reference to this Tautology, as the cnf transformation of a tautology T remains the same as the tautology.

Overrides:

getCNF in class ISent

Returns:

a reference to this Tautology.

getCNFUI

public ISent getCNFUI()

Returns a reference to this Tautology, as the cnf transformation of a tautology T remains the same as the tautology.

This method is invoked only by the ListSent constructors.

Overrides:

getCNFUI in class ISent

Returns:

a reference to this Tautology.

getDNFUI

public ISent getDNFUI()

Returns a reference to this Tautology, as the dnf transformation of a tautology T remains the same as the tautology.

This method is invoked only by the ListSent constructors.

Overrides:

getDNFUI in class ISent

Returns:

a reference to this Tautology.

getLabel

public java.lang.String getLabel()

Returns the string representation of this Tautology.

Overrides:

getLabel in class ISent

Returns:

the string representation T of this Tautology.

getLabelSB

java.lang.StringBuffer getLabelSB()

Returns null as this method is never invoked on this Tautology but implemented only to satisfy the abstract specification of ISent.

Specified by:

getLabelSB in class ISent

Returns:

null.

getAtoms

java.util.HashSet getAtoms()

Returns the empty set of literals of this Tautology.

Specified by:

getAtoms in class ISent

Returns:

the empty HashSet of literals of this Tautology.