Module org.chocosolver

Package org.chocosolver.solver.learn

Class ExplanationForSignedClause

java.lang.Object

org.chocosolver.solver.learn.IExplanation

org.chocosolver.solver.learn.ExplanationForSignedClause

public class ExplanationForSignedClause
extends IExplanation

An implementation of IExplanation dedicated to learn signed clauses

Project: choco-solver.

Since:

27/01/2017.

Author:

Charles Prud'homme

Field Summary

Fields

Modifier and Type	Field	Description
static boolean	ASSERT_NO_LEFT_BRANCH	Set to false when skip assertion that no left branch are backtracked to
static boolean	DEFAULT_X	Set to true to force all cause to use default explanations
static boolean	FINE_PROOF	FOR DEBUGGING PURPOSE ONLY.
static boolean	PROOF	FOR DEBUGGING PURPOSE ONLY.

Constructor Summary

Constructors

Constructor	Description
ExplanationForSignedClause(Implications ig)

Method Summary

Modifier and Type	Method	Description
void	addLiteral(IntVar var, IntIterableRangeSet dom, boolean pivot)	Add a signed literal (var ∈ dom) to this explanation.
void	extractConstraint(Model mModel, ClauseStore ngstore)	Extract and post the nogood related to this explanation
int	getAssertingLevel()
int	getCardinality()
IntIterableRangeSet	getComplementSet(IntVar var)
IntIterableRangeSet	getFreeSet()	Return an empty set available (created and returned) or create a new one
IntIterableRangeSet	getFreeSet(int val)	Return an available set (created and returned) or create a new one then add 'val' to it.
IntIterableRangeSet	getFreeSet(int a, int b)	Return an available set (created and returned) or create a new one then add range ['a','b'] to it.
ValueSortedMap<IntVar>	getFront()
HashMap<IntVar,IntIterableRangeSet>	getLiterals()
IntIterableRangeSet	getRootSet(IntVar var)
IntIterableRangeSet	getSet(int p)
IntIterableRangeSet	getSet(IntVar var)
void	learnSignedClause(ContradictionException cex)	From a given conflict, defined by cex and the current implication graph mIG, this method will compute the signed clause inferred from the conflict.
void	learnSolution(DecisionPath path)
void	recycle()	Recycle this explanation when it is not used anymore.
void	returnSet(IntIterableRangeSet set)
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

ASSERT_NO_LEFT_BRANCH

public static boolean ASSERT_NO_LEFT_BRANCH

Set to false when skip assertion that no left branch are backtracked to

DEFAULT_X

public static boolean DEFAULT_X

Set to true to force all cause to use default explanations

PROOF

public static boolean PROOF

FOR DEBUGGING PURPOSE ONLY. Set to true to output proofs

FINE_PROOF

public static boolean FINE_PROOF

FOR DEBUGGING PURPOSE ONLY. Set to true to output proofs with details

Constructor Detail

ExplanationForSignedClause

public ExplanationForSignedClause(Implications ig)

Method Detail

extractConstraint

public void extractConstraint(Model mModel,
                              ClauseStore ngstore)

Description copied from class: IExplanation

Extract and post the nogood related to this explanation

Specified by:

extractConstraint in class IExplanation

Parameters:

mModel - the model to post the nogood in

recycle

public void recycle()

Description copied from class: IExplanation

Recycle this explanation when it is not used anymore.

Specified by:

recycle in class IExplanation

learnSolution

public void learnSolution(DecisionPath path)

learnSignedClause

public void learnSignedClause(ContradictionException cex)

From a given conflict, defined by cex and the current implication graph mIG, this method will compute the signed clause inferred from the conflict. A call to extractConstraint(Model, ClauseStore) will return the computed result.

Parameters:

cex - the conflict

addLiteral

public void addLiteral(IntVar var,
                       IntIterableRangeSet dom,
                       boolean pivot)

Add a signed literal (var ∈ dom) to this explanation. This is achieved in three steps:

1. signed binary resolution (where 'v' is the pivot variable):

            (v ∈ A ∨ X), (v ∈ B ∨ Y) : (v ∈ (A∩B) ∨ X ∨ Y)
        

2. simplification:

                (v ∈ ∅ ∨ Z) : (Z)
            

3. join literals:

                ((∀i v ∈ Ai) ∨ Z) : (v ∈ (∪i Ai) ∨ Z)
            

Parameters:

var - signed literal variable

dom - signed literal domain

pivot - true if var is the pivot variable

getCardinality

public int getCardinality()

Returns:

the number of literals in this explanation

getAssertingLevel

public int getAssertingLevel()

Returns:

the decision to refute (ie, point to jump to wrt the current decision path).

getFreeSet

public IntIterableRangeSet getFreeSet()

Return an empty set available (created and returned) or create a new one

Returns:

a free set

getFreeSet

public IntIterableRangeSet getFreeSet(int val)

Return an available set (created and returned) or create a new one then add 'val' to it.

Returns:

a free set

getFreeSet

public IntIterableRangeSet getFreeSet(int a,
                                      int b)

Return an available set (created and returned) or create a new one then add range ['a','b'] to it.

Returns:

a free set

returnSet

public void returnSet(IntIterableRangeSet set)

getSet

public IntIterableRangeSet getSet(int p)

Parameters:

p - position

Returns:

a set which contains a copy of the domain of the var at position p

getSet

public IntIterableRangeSet getSet(IntVar var)

Parameters:

var - a variable

Returns:

a set which contains a copy of the domain of var at its front position

getComplementSet

public IntIterableRangeSet getComplementSet(IntVar var)

Parameters:

var - a variable

Returns:

a set which contains a copy of the complement domain of var at its front position wrt to its root domain

getRootSet

public IntIterableRangeSet getRootSet(IntVar var)

Parameters:

var - a variable

Returns:

a set which contains a copy of the root domain of var

getFront

public ValueSortedMap<IntVar> getFront()

getLiterals

public HashMap<IntVar,IntIterableRangeSet> getLiterals()

toString

public String toString()

Overrides:

toString in class Object