ASPHead

java.lang.Object
- org.tweetyproject.lp.asp.syntax.ASPElement
- - org.tweetyproject.lp.asp.syntax.ASPHead

All Implemented Interfaces:

Formula, ComplexLogicalFormula, LogicStructure, SimpleLogicalFormula

Direct Known Subclasses:

AggregateHead, ClassicalHead
```
public abstract class ASPHead
extends ASPElement
```
This class is a common base class for ASP formulas that can be part of an ASP rule head.

Author:

Anna Gessler

Constructor Summary

Constructors
Constructor Description

ASPHead()

Method Summary

Modifier and Type	Method	Description
`abstract java.util.Collection<? extends ASPLiteral>`	`getLiterals()`	Returns all literals in this element in form of a SortedSet.
`abstract boolean`	`isEmpty()`

Methods inherited from class org.tweetyproject.lp.asp.syntax.ASPElement
clone, containsTermsOfType, exchange, getAtoms, getPredicateCls, getPredicates, getSignature, isGround, isWellFormed, printToClingo, substitute, substitute

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.tweetyproject.logics.commons.syntax.interfaces.LogicStructure
getTerms, getTerms

Methods inherited from interface org.tweetyproject.logics.commons.syntax.interfaces.SimpleLogicalFormula
equals, hashCode, isLiteral

- Constructor Detail
  - ASPHead
```
public ASPHead()
```
- Method Detail
  - isEmpty
```
public abstract boolean isEmpty()
```
    Returns:
    
    true if the head is empty, false otherwise
  - getLiterals
```
public abstract java.util.Collection<? extends ASPLiteral> getLiterals()
```
    Returns all literals in this element in form of a SortedSet. Literals are atoms or strict negations of atoms.
    
    Returns:
    
    all the literals used in the rule element