revisionlogic
Class Contradiction

java.lang.Object
  revisionlogic.ISent
      revisionlogic.Contradiction

final class Contradiction

extends ISent

Contradiction represents a contradiction. 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)

Contradiction()

Method Summary

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

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

Contradiction

Contradiction()

Method Detail

clone

public java.lang.Object clone()

Returns a reference to this Contradiction.

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

Specified by:

clone in class ISent

Returns:

a reference to this Contradiction.

equals

public boolean equals(java.lang.Object s)

Checks if this Contradiction equals s.

Specified by:

equals in class ISent

Returns:

true if s is a Contradiction, false otherwise.

getDepth

int getDepth()

Returns the depth of this Contradiction.

Specified by:

getDepth in class ISent

Returns:

always 0 for the depth of this Contradiction.

getType

public int getType()

Returns the type of this Contradiction.

Specified by:

getType in class ISent

Returns:

an int indicating the contradiction type.

isConsistent

public boolean isConsistent()

Returns false to indicate this Contradiction is itself inconsistent.

Overrides:

isConsistent in class ISent

Returns:

always false to indicate this Contradiction is itself inconsistent.

implicationsOut

ISent implicationsOut()

Returns a reference to this Contradiction, as the cnf and dnf transformations of a contradiction F remain the same as the contradiction.

Specified by:

implicationsOut in class ISent

Returns:

a reference to this Contradiction.

negationsIn

ISent negationsIn()

Returns a reference to this Contradiction, as the cnf and dnf transformations of a contradiction F remain the same as the contradiction.

Specified by:

negationsIn in class ISent

Returns:

a reference to this Contradiction.

disjunctionsIn

ISent disjunctionsIn()

Returns a reference to this Contradiction, as the cnf transformation of a contradiction F remains the same as the contradiction.

Specified by:

disjunctionsIn in class ISent

Returns:

a reference to this Contradiction.

conjunctionsIn

ISent conjunctionsIn()

Returns a reference to this Contradiction, as the dnf transformation of a contradiction F remains the same as the contradiction.

Specified by:

conjunctionsIn in class ISent

Returns:

a reference to this Contradiction.

getCNF

public ISent getCNF()

Returns a reference to this Contradiction, as the cnf transformation of a contradiction F remains the same as the contradiction.

Overrides:

getCNF in class ISent

Returns:

a reference to this Contradiction.

getCNFUI

public ISent getCNFUI()

Returns a reference to this Contradiction, as the cnf transformation of a contradiction F remains the same as the contradiction.

This method is invoked only by the ListSent constructors.

Overrides:

getCNFUI in class ISent

Returns:

a reference to this Contradiction.

getDNFUI

public ISent getDNFUI()

Returns a reference to this Contradiction, as the dnf transformation of a contradiction F remains the same as the contradiction.

This method is invoked only by the ListSent constructors.

Overrides:

getDNFUI in class ISent

Returns:

a reference to this Contradiction.

getLabel

public java.lang.String getLabel()

Returns the string representation of this Contradiction.

Overrides:

getLabel in class ISent

Returns:

the string representation F of this Contradiction.

getLabelSB

java.lang.StringBuffer getLabelSB()

Returns null as this method is never invoked on this Contradiction 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 Contradiction.

Specified by:

getAtoms in class ISent

Returns:

the empty HashSet of literals of this Contradiction.