LBJ2.infer
Class PropositionalConstant

java.lang.Object
  LBJ2.infer.Constraint
      LBJ2.infer.PropositionalConstraint
          LBJ2.infer.PropositionalConstant

All Implemented Interfaces:

java.lang.Cloneable

public class PropositionalConstant
extends PropositionalConstraint

A propositional constant is either true or false.

Field Summary

protected boolean	constant The constant value.
static PropositionalConstant	False false
static PropositionalConstant	True true

Constructor Summary

PropositionalConstant(boolean v)
Initializing constructor.

Method Summary

PropositionalConstraint	CNF() Produces a new, logically simplified version of this constraint in conjunctive normal form (CNF).
void	consolidateVariables(java.util.AbstractMap m) Replaces all unquantified variables with the unique copy stored as a value of the given map; also instantiates all quantified variables and stores them in the given map.
PropositionalConstraint	DNF() Produces a new, logically simplified version of this constraint in disjunctive normal form (DNF).
boolean	equals(java.lang.Object o) Two PropositionalConstants are equivalent when their constants are equal.
boolean	evaluate() Determines whether the constraint is satisfied.
Constraint[]	getChildren() Returns the children of this constraint in an array.
int	hashCode() The hash code of a PropositionalConstant is the hash code of the Boolean object formed from the constant.
boolean	moreGeneralThan(PropositionalConstraint c) Compares topology to determine if this constraint is more general than the given constraint; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalAtLeast c) Compares topology to determine if this constraint is more specific than the given at-least; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalConjunction c) Compares topology to determine if this constraint is more specific than the given conjunction; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalConstant c) Compares topology to determine if this constraint is more specific than the given constant; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalDisjunction c) Compares topology to determine if this constraint is more specific than the given disjunction; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalDoubleImplication c) Compares topology to determine if this constraint is more specific than the given double implication; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalImplication c) Compares topology to determine if this constraint is more specific than the given implication; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalNegation c) Compares topology to determine if this constraint is more specific than the given negation; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalVariable c) Compares topology to determine if this constraint is more specific than the given variable; note: this method is not required to be correct when it answers false.
PropositionalConstraint	negate() Produces a new propositional constraint equivalent to this constraint and that contains no negated constraints other than variables.
void	runVisit(Inference infer) Calls the appropriate visit(·) method of the given Inference for this Constraint, as per the visitor pattern.
PropositionalConstraint	simplify() Produces a new, logically simplified version of this constraint, preserving variable consolidation.
void	write(java.lang.StringBuffer buffer) Creates a string respresentation of this constraint using the string representations of the objects involved.

Methods inherited from class LBJ2.infer.PropositionalConstraint

clone, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

True

public static final PropositionalConstant True

true

False

public static final PropositionalConstant False

false

constant

protected boolean constant

The constant value.

Constructor Detail

PropositionalConstant

public PropositionalConstant(boolean v)

Initializing constructor.

Parameters:

v - The value of this constant.

Method Detail

consolidateVariables

public void consolidateVariables(java.util.AbstractMap m)

Replaces all unquantified variables with the unique copy stored as a value of the given map; also instantiates all quantified variables and stores them in the given map.

Specified by:

consolidateVariables in class Constraint

Parameters:

m - The map in which to find unique copies of the variables.

evaluate

public boolean evaluate()

Determines whether the constraint is satisfied.

Specified by:

evaluate in class Constraint

simplify

public PropositionalConstraint simplify()

Produces a new, logically simplified version of this constraint, preserving variable consolidation.

Specified by:

simplify in class PropositionalConstraint

Returns:

A logically simplified version of this constraint.

See Also:

Constraint.consolidateVariables(java.util.AbstractMap)

negate

public PropositionalConstraint negate()

Produces a new propositional constraint equivalent to this constraint and that contains no negated constraints other than variables.

Specified by:

negate in class PropositionalConstraint

Returns:

A constraint representing the negation of this constraint.

CNF

public PropositionalConstraint CNF()

Produces a new, logically simplified version of this constraint in conjunctive normal form (CNF).

Specified by:

CNF in class PropositionalConstraint

Returns:

The conjunctive normal form of this constraint.

DNF

public PropositionalConstraint DNF()

Produces a new, logically simplified version of this constraint in disjunctive normal form (DNF).

Specified by:

DNF in class PropositionalConstraint

Returns:

The disjunctive normal form of this constraint.

getChildren

public Constraint[] getChildren()

Returns the children of this constraint in an array.

Specified by:

getChildren in class Constraint

Returns:

The children of this constraint in an array.

moreGeneralThan

public boolean moreGeneralThan(PropositionalConstraint c)

Compares topology to determine if this constraint is more general than the given constraint; note: this method is not required to be correct when it answers false.

Specified by:

moreGeneralThan in class PropositionalConstraint

Parameters:

c - The given constraint.

Returns:

true if a topological analysis determined that this constraint is more general than the given constraint.

moreSpecificThan

public boolean moreSpecificThan(PropositionalImplication c)

Compares topology to determine if this constraint is more specific than the given implication; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given implication.

Returns:

true if a topological analysis determined that this constraint is more specific than the given implication.

moreSpecificThan

public boolean moreSpecificThan(PropositionalDoubleImplication c)

Compares topology to determine if this constraint is more specific than the given double implication; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given double implication.

Returns:

true if a topological analysis determined that this constraint is more specific than the given double implication.

moreSpecificThan

public boolean moreSpecificThan(PropositionalConjunction c)

Compares topology to determine if this constraint is more specific than the given conjunction; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given conjunction.

Returns:

true if a topological analysis determined that this constraint is more specific than the given conjunction.

moreSpecificThan

public boolean moreSpecificThan(PropositionalDisjunction c)

Compares topology to determine if this constraint is more specific than the given disjunction; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given disjunction.

Returns:

true if a topological analysis determined that this constraint is more specific than the given disjunction.

moreSpecificThan

public boolean moreSpecificThan(PropositionalAtLeast c)

Compares topology to determine if this constraint is more specific than the given at-least; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given at-least.

Returns:

true if a topological analysis determined that this constraint is more specific than the given disjunction.

moreSpecificThan

public boolean moreSpecificThan(PropositionalNegation c)

Compares topology to determine if this constraint is more specific than the given negation; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given negation.

Returns:

true if a topological analysis determined that this constraint is more specific than the given negation.

moreSpecificThan

public boolean moreSpecificThan(PropositionalVariable c)

Compares topology to determine if this constraint is more specific than the given variable; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given variable.

Returns:

true if a topological analysis determined that this constraint is more specific than the given variable.

moreSpecificThan

public boolean moreSpecificThan(PropositionalConstant c)

Compares topology to determine if this constraint is more specific than the given constant; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given constant.

Returns:

true if a topological analysis determined that this constraint is more specific than the given constant.

hashCode

public int hashCode()

The hash code of a PropositionalConstant is the hash code of the Boolean object formed from the constant.

Overrides:

hashCode in class java.lang.Object

Returns:

The hash code for this PropositionalConstant.

equals

public boolean equals(java.lang.Object o)

Two PropositionalConstants are equivalent when their constants are equal.

Overrides:

equals in class java.lang.Object

Returns:

true iff the argument is a PropositionalConstant set to the same value as this constant.

runVisit

public void runVisit(Inference infer)

Calls the appropriate visit(·) method of the given Inference for this Constraint, as per the visitor pattern.

Specified by:

runVisit in class Constraint

Parameters:

infer - The inference visiting this constraint.

write

public void write(java.lang.StringBuffer buffer)

Creates a string respresentation of this constraint using the string representations of the objects involved.

Specified by:

write in class PropositionalConstraint

Parameters:

buffer - The output of this method will be appended to this buffer.