de.uni_tuebingen.sfb.lichtenstein.formulas
Class Inclusion

java.lang.Object
  de.uni_tuebingen.sfb.lichtenstein.formulas.FormulaImpl
      de.uni_tuebingen.sfb.lichtenstein.formulas.AtomicFormula
          de.uni_tuebingen.sfb.lichtenstein.formulas.Inclusion

All Implemented Interfaces:

Formula, Visitable, Serializable

public class Inclusion
extends AtomicFormula

A class representing inclusion of a first order variable in a set denotator.

Author:

Hendrik Maryns

See Also:

Serialized Form

Constructor Summary

Inclusion(FirstOrderVariable included, SetDenotator containing)
Initialize a new inclusion, taking two variables as arguments.

Method Summary

void	accept(FormulaVisitor visitor) Accept a formula visitor.
boolean	containsVariable(Variable var) Returns whether this formula contains the given variable.
boolean	equals(Object other) Indicates whether some other object is "equal to" this one.
SetDenotator	getContainingVariable() Returns the containing variable.
int	getFirstIndexOf(Variable var) Get the first index at which the given variable occurs.
FirstOrderVariable	getIncludedVariable() Returns the included variable.
int	getNbVariables() Returns the number of variables in this formula.
Set<Predicate>	getPredicates() Return all predicates in this formula.
Variable	getVariableAt(int index) Get the indexth variable (free or bound).
int	hashCode() Returns a hash code value for the object.
String	toString() Returns a string representation of the object.

Methods inherited from class de.uni_tuebingen.sfb.lichtenstein.formulas.AtomicFormula

getNbBoundVariables, getNbFreeVariables, getNormalForm, isFreeVariable

Methods inherited from class de.uni_tuebingen.sfb.lichtenstein.formulas.FormulaImpl

and, exists, exists, forAll, forAll, getFreeVariables, getVariables, iff, implies, isClosed, not, or

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Inclusion

public Inclusion(FirstOrderVariable included,
                 SetDenotator containing)

Initialize a new inclusion, taking two variables as arguments.

Parameters:

included - The variable which is included in the other variable.

containing - The variable which includes the other variable.

Precondition:

Both variables must be effective.

| included != null && containing != null

Postcondition:

The included variable is set to the given included variable.

| new.getIncludedVariable() == included

Postcondition:

The containing variable is set to the given containing variable.

| new.getContainingVariable() ==
       containing

Method Detail

getIncludedVariable

public FirstOrderVariable getIncludedVariable()

Returns the included variable.

Returns:

This is the first variable.

| result == getVariableAt(0)

getContainingVariable

public SetDenotator getContainingVariable()

Returns the containing variable.

Returns:

This is the second variable.

| result == getVariableAt(1)

getNbVariables

public int getNbVariables()

Returns the number of variables in this formula.

Returns:

If the containing variable is a predicate, 1, otherwise, 2.

getFirstIndexOf

public int getFirstIndexOf(Variable var)

Get the first index at which the given variable occurs.

Parameters:

var - The variable of which the index is wanted.

getVariableAt

public Variable getVariableAt(int index)
                       throws IndexOutOfBoundsException

Get the indexth variable (free or bound).

Parameters:

index - The index of the wanted variable

containsVariable

public boolean containsVariable(Variable var)

Returns whether this formula contains the given variable.

Parameters:

var - The variable to check.

Returns:

True if the given variable is the same as the included variable.

| result ==
         getIncludedVariable().equals(var)
|| getContainingVariable().equals(var)

getPredicates

public Set<Predicate> getPredicates()

Return all predicates in this formula.

Returns:

Only the including variable can be a predicate.

| if ( getIncludingVariable() instanceof Predicate ) |
         then result.contains(getContainingVariable())
| else result.isEmpty()

equals

public boolean equals(Object other)

Indicates whether some other object is "equal to" this one.

Overrides:

equals in class FormulaImpl

Returns:

Two inclusion atomic formulas are equal if they compare the same variables.

| let otherIn = (Inclusion)
         other in
| if ( otherIn.getIncludedVariable() == getIncludedVariable() ) | then result == false | else if (
         otherIn.getContainingVariable() == getContainingVariable() )
| then result == false | else result == true

hashCode

public int hashCode()

Returns a hash code value for the object.

Specified by:

hashCode in class FormulaImpl

Returns:

The hash code is based on the hash codes of the variables and of the characteristic symbol.

| result ==
         getIncludedVariable().hashCode() + "∈".hashCode() + getContainingVariable().hashCode()

toString

public String toString()

Returns a string representation of the object.

Specified by:

toString in class FormulaImpl

Returns:

The string representations of the variables are given, with the unicode symbol ELEMENT OF: ∈ in between them.

| result == getIncludedVariable().toString() + "∈" +
         getContainingVariable().toString()

accept

public void accept(FormulaVisitor visitor)
            throws de.uni_tuebingen.sfb.lichtenstein.exceptions.VisitorException

Accept a formula visitor. The iteration is done by the visitor, not by the composed formulas.

Specified by:

accept in interface Visitable

Overrides:

accept in class FormulaImpl

Parameters:

visitor - The visitor that is to be accepted to do its work.

Throws:

VisitorException

A visitor can throw an exception.