Package org.tweetyproject.lp.asp.syntax

Class AggregateAtom

java.lang.Object
org.tweetyproject.lp.asp.syntax.ASPElement
org.tweetyproject.lp.asp.syntax.ASPBodyElement
org.tweetyproject.lp.asp.syntax.AggregateAtom
All Implemented Interfaces:
Formula, ComplexLogicalFormula, LogicStructure, SimpleLogicalFormula
public class AggregateAtom extends ASPBodyElement
This class represents an aggregate. Aggregates are functions that range over sets of terms and literals and evaluate to some value. For example, using the aggregate function #count one can easily express "the number of employees of a department has to be greater than 0".
An aggregate function together with the terms and literals it ranges over and a comparison (like >= 0) is called an aggregate atom and can appear in the body of a rule.
If you want to use an aggregate atom as the head of a rule (as is allowed in some standards like clingo), use AggregateHead
Author:
Tim Janus, Thomas Vengels, Anna Gessler

  • Constructor Details

    • AggregateAtom

      public AggregateAtom()
      Empty default constructor.

    • AggregateAtom

      public AggregateAtom(ASPOperator.AggregateFunction function, List<AggregateElement> elements)
      Creates a new Aggregate with the given aggregate function and the given aggregate elements.
      Parameters:
      function - an aggregate function
      elements - list of aggregate elements

    • AggregateAtom

      public AggregateAtom(ASPOperator.AggregateFunction function, List<AggregateElement> elements, ASPOperator.BinaryOperator rightRelation, Term<?> rightBound)
      Creates a new Aggregate of the form "#func { elements } op rightBound" with the given aggregate function #func, the given aggregate elements, the given aggregate relation op and the given rightBound.
      Parameters:
      function - an aggregate function
      elements - list of aggregate elements
      rightRelation - the relation
      rightBound - some term

    • AggregateAtom

      public AggregateAtom(ASPOperator.AggregateFunction function, List<AggregateElement> elements, ASPOperator.BinaryOperator rightRelation, int rightBound)
      Creates a new Aggregate of the form "#func { elements } op rightBound" with the given aggregate function #func, the given aggregate elements, the given aggregate relation op and the given rightBound.
      Parameters:
      function - an aggregate function
      elements - list of aggregate elements
      rightRelation - the relation
      rightBound - integer

    • AggregateAtom

      public AggregateAtom(ASPOperator.AggregateFunction function, List<AggregateElement> elements, ASPOperator.BinaryOperator leftRelation, Term<?> leftBound, ASPOperator.BinaryOperator rightRelation, Term<?> rightBound)
      Creates a new Aggregate of the form "leftBound leftOp #func { elements } rightOp rightBound" with the given aggregate function, the given aggregate elements, and the given left and right aggregate relations and bounds.
      Parameters:
      function - an aggregate function
      elements - list of aggregate elements
      leftRelation -
      leftBound - term
      rightRelation -
      rightBound - term

    • AggregateAtom

      public AggregateAtom(ASPOperator.AggregateFunction function, List<AggregateElement> elements, ASPOperator.BinaryOperator leftRelation, int leftBound, ASPOperator.BinaryOperator rightRelation, int rightBound)
      Creates a new Aggregate of the form "leftBound op #func { elements } op rightBound" with the given aggregate function, the given aggregate elements, and the given left and right aggregate relations and integer bounds.
      Parameters:
      function - an aggregate function
      elements - list of aggregate elements
      leftRelation -
      leftBound - integer
      rightRelation -
      rightBound - integer

    • AggregateAtom

      public AggregateAtom(List<ASPBodyElement> literals, int leftBound, int rightBound)
      Creates a new cardinality rule, meaning an aggregate of the form "leftBound <= #count { elements } <= rightBound" with the given literals and the given integer bounds.
      Parameters:
      literals - of the cardinality rule
      leftBound - of the cardinality rule
      rightBound - of the cardinality rule

    • AggregateAtom

      public AggregateAtom(AggregateAtom other)
      Copy-Constructor
      Parameters:
      other - another AggregateAtom

  • 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 AggregateAtom 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 AggregateAtom 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

    • 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

    • 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

    • getAggregateElements

      public List<AggregateElement> getAggregateElements()
      Returns:
      the elements that the aggregate ranges over.

    • setAggregateElements

      public void setAggregateElements(List<AggregateElement> aggregateElements)
      Set the elements that the aggregate ranges over.
      Parameters:
      aggregateElements -

    • hasLeftRelation

      public boolean hasLeftRelation()
      Returns true if the aggregate has a left aggregate relation (meaning a term that the aggregate's resulting value will be compared to using a comparative operator).
      Returns:
      true if aggregate has left aggregate relation

    • hasRightRelation

      public boolean hasRightRelation()
      Returns true if the aggregate has a right aggregate relation (meaning a term that the aggregate's resulting value will be compared to using a comparative operator).
      Returns:
      true if aggregate has right aggregate relation

    • getFunction

      public ASPOperator.AggregateFunction getFunction()
      Returns:
      the aggregate function

    • setFunction

      public void setFunction(ASPOperator.AggregateFunction function)
      Sets the aggregate function.
      Parameters:
      function - an aggregate function

    • getRightOperator

      public ASPOperator.BinaryOperator getRightOperator()
      Returns the operator of the right aggregate relation.
      Returns:
      comparative operator

    • setRightOperator

      public void setRightOperator(ASPOperator.BinaryOperator op)
      Sets the operator of the right aggregate relation.
      Parameters:
      op - comparative operator

    • getRightGuard

      public Term<?> getRightGuard()
      Returns:
      the right relation term (right guard).

    • setRightGuard

      public void setRightGuard(Term<?> relationTerm)
      Set the right relation term (right guard).
      Parameters:
      relationTerm - some term

    • setRightGuard

      public void setRightGuard(int relationTerm)
      Set the right relation term (right guard).
      Parameters:
      relationTerm - some integer

    • setRight

      public void setRight(Term<?> term, ASPOperator.BinaryOperator op)
      Set the right relation term and operator.
      Parameters:
      term -
      op -

    • setRight

      public void setRight(int term, ASPOperator.BinaryOperator op)
      Set the right relation term and operator.
      Parameters:
      term - , an integer
      op -

    • getLeftOperator

      public ASPOperator.BinaryOperator getLeftOperator()
      Returns the operator of the left aggregate relation.
      Returns:
      comparative operator

    • setLeftOperator

      public void setLeftOperator(ASPOperator.BinaryOperator op)
      Sets the operator of the left aggregate relation.
      Parameters:
      op - comparative operator

    • getLeftGuard

      public Term<?> getLeftGuard()
      Get the left relation term (left guard).
      Returns:
      Term

    • setLeftGuard

      public void setLeftGuard(Term<?> relationTerm)
      Set the left relation term (left guard).
      Parameters:
      relationTerm - some term

    • setLeftGuard

      public void setLeftGuard(int relationTerm)
      Set the left relation term (left guard).
      Parameters:
      relationTerm - some integer

    • setLeft

      public void setLeft(Term<?> term, ASPOperator.BinaryOperator op)
      Set the left relation term and operator.
      Parameters:
      term -
      op -

    • setLeft

      public void setLeft(int term, ASPOperator.BinaryOperator op)
      Set the left relation term and operator.
      Parameters:
      term - , an integer
      op -

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • printToClingo

      public String printToClingo()
      Description copied from class: ASPElement
      Returns a representation of this ASP element in clingo (potassco) syntax. See https://potassco.org/ for more information.
      Overrides:
      printToClingo in class ASPElement
      Returns:
      String representation in clingo syntax

    • 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