Class SimpleRelationalCReasoner
java.lang.Object
org.tweetyproject.logics.rcl.reasoner.SimpleRelationalCReasoner
- All Implemented Interfaces:
ModelProvider<RelationalConditional,RclBeliefSet,RelationalRankingFunction>
,QualitativeReasoner<RclBeliefSet,FolFormula>
,Reasoner<Boolean,RclBeliefSet,FolFormula>
public class SimpleRelationalCReasoner
extends Object
implements QualitativeReasoner<RclBeliefSet,FolFormula>, ModelProvider<RelationalConditional,RclBeliefSet,RelationalRankingFunction>
This class models a relational brute force c-reasoner for relational conditional logic. Reasoning is performed
by computing a minimal c-representation for the given knowledge base.
A c-representation for a conditional knowledge base R={r1,...,rn} is a ranking function k such that k accepts every conditional in R (k |= R) and if there are numbers k0,k1+,k1-,...,kn+,kn- with
k(w)=k0 + \sum_{w verifies ri} ki+ + \sum_{w falsifies ri} kj- for every w. A c-representation is minimal if k0+...+kn- is minimal.
The c-representation is computed using a brute force approach.
See Gabriele Kern-Isberner. Conditionals in nonmonotonic reasoning and belief revision. Lecture Notes in Computer Science, Volume 2087. 2001.
See also [Kern-Isberner,Thimm, "A Ranking Semantics for Relational Defaults", in preparation].
A c-representation for a conditional knowledge base R={r1,...,rn} is a ranking function k such that k accepts every conditional in R (k |= R) and if there are numbers k0,k1+,k1-,...,kn+,kn- with
k(w)=k0 + \sum_{w verifies ri} ki+ + \sum_{w falsifies ri} kj- for every w. A c-representation is minimal if k0+...+kn- is minimal.
The c-representation is computed using a brute force approach.
See Gabriele Kern-Isberner. Conditionals in nonmonotonic reasoning and belief revision. Lecture Notes in Computer Science, Volume 2087. 2001.
See also [Kern-Isberner,Thimm, "A Ranking Semantics for Relational Defaults", in preparation].
- Author:
- Matthias Thimm
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Constructor Summary
ConstructorDescriptionSimpleRelationalCReasoner(boolean simple)
Creates a new relational c-representation reasoner. -
Method Summary
Modifier and TypeMethodDescriptiongetModel(RclBeliefSet bbase)
Returns a single (dedicated) model of the given belief base.getModel(RclBeliefSet bs, FolSignature signature)
Retrieves the C representation of the given belief set wrt.getModels(RclBeliefSet bbase)
Returns a characterizing model of the given belief basequery(RclBeliefSet bs, FolFormula query)
Queries the given belief base for the given formula.query(RclBeliefSet bs, FolFormula query, FolSignature signature)
Queries the given belief set wrt.
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Constructor Details
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SimpleRelationalCReasoner
public SimpleRelationalCReasoner(boolean simple)Creates a new relational c-representation reasoner.- Parameters:
simple
- whether the computed c-representation is simple.
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Method Details
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query
Queries the given belief set wrt. the given signature.- Parameters:
bs
- some belief setquery
- some querysignature
- some signature- Returns:
- true iff the query is true
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query
Description copied from interface:Reasoner
Queries the given belief base for the given formula.- Specified by:
query
in interfaceQualitativeReasoner<RclBeliefSet,FolFormula>
- Specified by:
query
in interfaceReasoner<Boolean,RclBeliefSet,FolFormula>
- Parameters:
bs
- a belief basequery
- a formula- Returns:
- the answer to the query
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getModels
Description copied from interface:ModelProvider
Returns a characterizing model of the given belief base- Specified by:
getModels
in interfaceModelProvider<RelationalConditional,RclBeliefSet,RelationalRankingFunction>
- Parameters:
bbase
- some belief base- Returns:
- the (selected) models of the belief base
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getModel
Description copied from interface:ModelProvider
Returns a single (dedicated) model of the given belief base. If the implemented method allows for more than one dedicated model, the selection may be non-deterministic.- Specified by:
getModel
in interfaceModelProvider<RelationalConditional,RclBeliefSet,RelationalRankingFunction>
- Parameters:
bbase
- some belief base- Returns:
- a selected model of the belief base.
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getModel
Retrieves the C representation of the given belief set wrt. the given signature- Parameters:
bs
- some belief setsignature
- some signature- Returns:
- the c representation (a ranking function)
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