Package org.tweetyproject.lp.asp.syntax

Class Program

java.lang.Object

java.util.AbstractCollection<ASPRule>

java.util.AbstractSet<ASPRule>

java.util.HashSet<ASPRule>

org.tweetyproject.commons.util.rules.RuleSet<ASPRule>

org.tweetyproject.lp.asp.syntax.Program

All Implemented Interfaces:

Serializable, Cloneable, Iterable<ASPRule>, Collection<ASPRule>, Set<ASPRule>, BeliefBase, LogicProgram<ClassicalHead,ASPBodyElement,ASPRule>

public class Program
extends RuleSet<ASPRule>
implements LogicProgram<ClassicalHead,ASPBodyElement,ASPRule>

This class models an ASP-Core-2 program, meaning a set of rules and optionally a query. A program is ground if it contains no variables. The rules are ordered alphabetically.

Author:

Tim Janus, Thomas Vengels, Anna Gessler

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
Program()	Creates a new empty program.
Program(Collection<ASPRule> rules)	Creates a new program with the given rules.
Program(ASPLiteral query, Set<ASPRule> rules)	Creates a new program with the given query and rules.
Program(ASPRule... rules)	Creates a new program with the given rules.
Program(Program other)	Copy-Constructor

Method Summary

Modifier and Type	Method	Description
void	add(Program other)	Adds another program's content to the content of this program.
void	addFact(ASPLiteral fact)	Adds a fact to this program.
void	addFact(ClassicalHead fact)	Adds the given fact to the program
void	addFacts(ClassicalHead... fact)	Adds the given facts to the program
boolean	addToOutputWhitelist(Predicate p)	Adds the given predicate to the whitelist of predicates.
Program	clone()
boolean	equals(Object obj)
Program	exchange(Term<?> v, Term<?> t)	Substitutes all occurrences of term "v" in this formula by term "t" and at the same time replaces all occurrences of term "t" by term "v" and eventually returns the new formula.
Set<String>	getAdditionalOptions()
static Program	getDefaultification(Program p)	Creates the defaultification p_d of a given program p.
FolSignature	getMinimalSignature()	Returns the signature of the language of this knowledge base.
Set<Predicate>	getOutputWhitelist()	Returns the whitelist of predicates.
ASPLiteral	getQuery()	Returns the query of the program, if there is one.
Program	getReduct(Set<ASPLiteral> state)	Returns the reduct of this program wrt.
int	hashCode()
boolean	hasQuery()	Returns true if the program contains a query.
boolean	isExtendedProgram()	Checks if the program is an extended program, meaning the heads of the literals do not have more than one literal.
boolean	isGround()	Checks if the program is ground, meaning if it contains no rules with variables.
boolean	isSafe()	Returns true if the program is safe, i.e.
void	setAdditionalOptions(Set<String> additionalOptions)	Set additional options for solvers.
void	setOutputWhitelist(Collection<Predicate> ps)	Sets the whitelist of predicates.
void	setQuery(ASPLiteral query)	Sets the query of the program.
Program	substitute(Map<? extends Term<?>,? extends Term<?>> map)	Substitutes all occurrences of all terms "v" in map.keyset() in this formula by map.get(v) and returns the new formula.
Program	substitute(Term<?> v, Term<?> t)	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.commons.util.rules.RuleSet

getConclusions, getPremises, getRulesWithConclusion, getSyntacticModule

Methods inherited from class java.util.HashSet

add, clear, contains, isEmpty, iterator, newHashSet, remove, size, spliterator, toArray, toArray

Methods inherited from class java.util.AbstractSet

removeAll

Methods inherited from class java.util.AbstractCollection

addAll, containsAll, retainAll

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.Set

addAll, containsAll, removeAll, retainAll

Constructor Details

Program

public Program()

Creates a new empty program.

Program

public Program(Collection<ASPRule> rules)

Creates a new program with the given rules.

Parameters:

rules - a set of rules

Program

public Program(ASPRule... rules)

Creates a new program with the given rules.

Parameters:

rules - a set of rules

Program

public Program(ASPLiteral query,
 Set<ASPRule> rules)

Creates a new program with the given query and rules.

Parameters:

query - a query

rules - a set of rules

Program

public Program(Program other)

Copy-Constructor

Parameters:

other - another program

Method Details

setQuery

public void setQuery(ASPLiteral query)

Sets the query of the program.

Parameters:

query - a literal

addFact

public void addFact(ClassicalHead fact)

Description copied from interface: LogicProgram

Adds the given fact to the program

Specified by:

addFact in interface LogicProgram<ClassicalHead,ASPBodyElement,ASPRule>

Parameters:

fact - a fact

addFacts

public void addFacts(ClassicalHead... fact)

Description copied from interface: LogicProgram

Adds the given facts to the program

Specified by:

addFacts in interface LogicProgram<ClassicalHead,ASPBodyElement,ASPRule>

Parameters:

fact - some facts

setOutputWhitelist

public void setOutputWhitelist(Collection<Predicate> ps)

Sets the whitelist of predicates. Solvers that use this option will only show atoms over predicates in this set in their output.

Parameters:

ps - set of predicates

addToOutputWhitelist

public boolean addToOutputWhitelist(Predicate p)

Adds the given predicate to the whitelist of predicates. Solvers that use this option will only show atoms over predicates in this set in their output.

Parameters:

p - a Predicate

Returns:

if the whitelist did not already contain the specified element

getOutputWhitelist

public Set<Predicate> getOutputWhitelist()

Returns the whitelist of predicates. Solvers that use this option will only show atoms over predicates in this set in their output.

Returns:

set of whitelisted predicates

hasQuery

public boolean hasQuery()

Returns true if the program contains a query.

Returns:

true if the program has a query, false otherwise

getQuery

public ASPLiteral getQuery()

Returns the query of the program, if there is one.

Returns:

a literal, or null if the program has no query

addFact

public void addFact(ASPLiteral fact)

Adds a fact to this program.

Parameters:

fact - a literal

add

public void add(Program other)

Adds another program's content to the content of this program.

Parameters:

other - Reference to the other program.

getAdditionalOptions

public Set<String> getAdditionalOptions()

Returns:

additional options for solvers

setAdditionalOptions

public void setAdditionalOptions(Set<String> additionalOptions)

Set additional options for solvers.

Parameters:

additionalOptions - commandLineArguments in the format "option=value"

isExtendedProgram

public boolean isExtendedProgram()

Checks if the program is an extended program, meaning the heads of the literals do not have more than one literal.

Returns:

True if the program is an extended program, false otherwise.

isSafe

public boolean isSafe()

Returns true if the program is safe, i.e. if all of its rules and its query are safe according to the definition of safety given in the ASP-Core-2 standard.

Returns:

true if the program is safe, false otherwise

isGround

public boolean isGround()

Checks if the program is ground, meaning if it contains no rules with variables.

Returns:

true if the program is ground, false otherwise

getMinimalSignature

public FolSignature getMinimalSignature()

Description copied from interface: BeliefBase

Returns the signature of the language of this knowledge base.

Specified by:

getMinimalSignature in interface BeliefBase

Specified by:

getMinimalSignature in interface LogicProgram<ClassicalHead,ASPBodyElement,ASPRule>

Returns:

the signature of the language of this knowledge base.

substitute

public Program substitute(Term<?> v,
 Term<?> t)
                   throws IllegalArgumentException

Description copied from interface: LogicProgram

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

Specified by:

substitute in interface LogicProgram<ClassicalHead,ASPBodyElement,ASPRule>

Parameters:

v - the term to be substituted.

t - the term to substitute.

Returns:

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

Throws:

IllegalArgumentException - if "v" and "t" are of different sorts

substitute

public Program substitute(Map<? extends Term<?>,? extends Term<?>> map)
                   throws IllegalArgumentException

Description copied from interface: LogicProgram

Substitutes all occurrences of all terms "v" in map.keyset() in this formula by map.get(v) and returns the new formula.

Specified by:

substitute in interface LogicProgram<ClassicalHead,ASPBodyElement,ASPRule>

Parameters:

map - a mapping defining which terms to be substituted.

Returns:

a formula where every term in map.keyset() has been replaced by map.get(v).

Throws:

IllegalArgumentException - if any term and its mapping are of different sorts

exchange

public Program exchange(Term<?> v,
 Term<?> t)
                 throws IllegalArgumentException

Description copied from interface: LogicProgram

Substitutes all occurrences of term "v" in this formula by term "t" and at the same time replaces all occurrences of term "t" by term "v" and eventually returns the new formula.

Specified by:

exchange in interface LogicProgram<ClassicalHead,ASPBodyElement,ASPRule>

Parameters:

v - a term.

t - a term.

Returns:

a new logical formula with both "v" and "t" exchanged.

Throws:

IllegalArgumentException - if "v" and "t" are of different sorts

clone

public Program clone()

Overrides:

clone in class HashSet<ASPRule>

getReduct

public Program getReduct(Set<ASPLiteral> state)

Returns the reduct of this program wrt. the given state, i.e. a program that contains no default negation and only those rules of this program (without all default-negated literals in the body) that do not have a default-negated version of a literal in their body.

Parameters:

state - some set of literals

Returns:

the reduct of this program

getDefaultification

public static Program getDefaultification(Program p)

Creates the defaultification p_d of a given program p. A defaultificated program p' of p adds for every Rule r in p a modified rule r_d of the form: 'H(r) :- B(r), not -H(r).' to the program p'.

Parameters:

p - The program which is not defaultificated yet

Returns:

a program p' which is the defaultificated version of p.

toString

public String toString()

Specified by:

toString in interface BeliefBase

Specified by:

toString in interface LogicProgram<ClassicalHead,ASPBodyElement,ASPRule>

Overrides:

toString in class AbstractCollection<ASPRule>

hashCode

public int hashCode()

Specified by:

hashCode in interface Collection<ASPRule>

Specified by:

hashCode in interface Set<ASPRule>

Overrides:

hashCode in class AbstractSet<ASPRule>

equals

public boolean equals(Object obj)

Specified by:

equals in interface Collection<ASPRule>

Specified by:

equals in interface Set<ASPRule>

Overrides:

equals in class AbstractSet<ASPRule>