Package org.tweetyproject.lp.asp.syntax

Class ComparativeAtom

java.lang.Object

org.tweetyproject.lp.asp.syntax.ASPElement

org.tweetyproject.lp.asp.syntax.ASPBodyElement

org.tweetyproject.lp.asp.syntax.ComparativeAtom

All Implemented Interfaces:

Formula, ComplexLogicalFormula, LogicStructure, SimpleLogicalFormula

public class ComparativeAtom
extends ASPBodyElement

This class represents a comparative atom, meaning an expression of the form 't x u' where t,u are terms and x is in {<, <=, ==, !=, >, >=}. Comparative atoms are called "Built-in atoms" in the ASP-Core-2 standard.

Author:

Tim Janus, Thomas Vengels, Anna Gessler

Constructor Summary

Constructors

Constructor	Description
ComparativeAtom(ASPOperator.BinaryOperator op, Term<?> left, Term<?> right)	Create a new comparative atom with the given operator and left and right term.
ComparativeAtom(ComparativeAtom other)	Copy-Constructor

Method Summary

Modifier and Type	Method	Description
ASPBodyElement	clone()	Creates a deep copy of this formula
boolean	equals(Object obj)
Set<ASPAtom>	getAtoms()	Processes the set of all atoms which appear in this formula
Term<?>	getLeft()
SortedSet<ASPLiteral>	getLiterals()	Returns all literals in this element in form of a SortedSet.
ASPOperator.BinaryOperator	getOperator()
Class<? extends Predicate>	getPredicateCls()
Set<Predicate>	getPredicates()	Processes the set of all predicates which appear in this formula
Term<?>	getRight()
FolSignature	getSignature()	Returns the signature of the language of this formula.
Set<Term<?>>	getTerms()
<C extends Term<?>> Set<C>	getTerms(Class<C> cls)	Processes the set containing all terms of type C.
int	hashCode()
boolean	isLiteral()
String	printToDLV()	Returns a representation of this ASP element in DLV syntax.
ComparativeAtom	substitute(Term<?> t, Term<?> v)	Substitutes all occurrences of term "v" in this formula by term "t" and returns the new formula.
String	toString()

Methods inherited from class org.tweetyproject.lp.asp.syntax.ASPElement

containsTermsOfType, exchange, isGround, isWellFormed, printToClingo, substitute

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Details

ComparativeAtom

public ComparativeAtom(ASPOperator.BinaryOperator op,
 Term<?> left,
 Term<?> right)

Create a new comparative atom with the given operator and left and right term.

Parameters:

op - a binary operator

left - term

right - term

ComparativeAtom

public ComparativeAtom(ComparativeAtom other)

Copy-Constructor

Parameters:

other - another ComparativeAtom

Method Details

getLiterals

public SortedSet<ASPLiteral> getLiterals()

Description copied from class: ASPBodyElement

Returns all literals in this element in form of a SortedSet. Literals are atoms or strict negations of atoms.

Specified by:

getLiterals in class ASPBodyElement

Returns:

all the literals used in the rule element

getPredicates

public Set<Predicate> getPredicates()

Description copied from interface: SimpleLogicalFormula

Processes the set of all predicates which appear in this formula

Specified by:

getPredicates in interface SimpleLogicalFormula

Specified by:

getPredicates in class ASPElement

Returns:

all predicates that appear in this formula

getAtoms

public Set<ASPAtom> getAtoms()

Description copied from interface: SimpleLogicalFormula

Processes the set of all atoms which appear in this formula

Specified by:

getAtoms in interface SimpleLogicalFormula

Specified by:

getAtoms in class ASPElement

Returns:

The set of all atoms

substitute

public ComparativeAtom substitute(Term<?> t,
 Term<?> v)

Description copied from interface: ComplexLogicalFormula

Substitutes all occurrences of term "v" in this formula by term "t" and returns the new formula.

Specified by:

substitute in interface ComplexLogicalFormula

Specified by:

substitute in class ASPBodyElement

Parameters:

t - the term to be substituted.

v - the term to substitute.

Returns:

a formula where every occurrence of "v" is replaced by "t".

getSignature

public FolSignature getSignature()

Description copied from interface: Formula

Returns the signature of the language of this formula.

Specified by:

getSignature in interface Formula

Specified by:

getSignature in class ASPElement

Returns:

the signature of the language of this formula.

clone

public ASPBodyElement clone()

Description copied from interface: SimpleLogicalFormula

Creates a deep copy of this formula

Specified by:

clone in interface ComplexLogicalFormula

Specified by:

clone in interface SimpleLogicalFormula

Specified by:

clone in class ASPElement

Returns:

the cloned formula

getPredicateCls

public Class<? extends Predicate> getPredicateCls()

Specified by:

getPredicateCls in interface SimpleLogicalFormula

Overrides:

getPredicateCls in class ASPElement

Returns:

The class description of the predicate used by this formula.

isLiteral

public boolean isLiteral()

Returns:

true if the formula represents a literal in the language or false otherwise

getTerms

public Set<Term<?>> getTerms()

Returns:

a set containing all terms of this logical structure

getOperator

public ASPOperator.BinaryOperator getOperator()

Returns:

the comparative operator of the atom.

getLeft

public Term<?> getLeft()

Returns:

the left (first) term of the comparative atom.

getRight

public Term<?> getRight()

Returns:

the right (second) term of the comparative atom.

getTerms

public <C extends Term<?>> Set<C> getTerms(Class<C> cls)

Description copied from interface: LogicStructure

Processes the set containing all terms of type C. This method uses the equals method of the given Class and therefore does not add terms which are sub classes of type C to the set.

Type Parameters:

C - the type of terms

Parameters:

cls - The Class structure containing type information about the searched term

Returns:

A set containing all terms of type C of this logical structure

toString

public String toString()

Overrides:

toString in class Object

printToDLV

public String printToDLV()

Description copied from class: ASPElement

Returns a representation of this ASP element in DLV syntax. See http://www.dlvsystem.com/html/DLV_User_Manual.html for more information.

Overrides:

printToDLV in class ASPElement

Returns:

String representation in DLV syntax

hashCode

public int hashCode()

Specified by:

hashCode in interface SimpleLogicalFormula

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Specified by:

equals in interface SimpleLogicalFormula

Overrides:

equals in class Object