Package org.tweetyproject.logics.fol.reasoner

Class SpassFolReasoner

java.lang.Object

org.tweetyproject.logics.fol.reasoner.FolReasoner

org.tweetyproject.logics.fol.reasoner.SpassFolReasoner

All Implemented Interfaces:

QualitativeReasoner<FolBeliefSet,FolFormula>, Reasoner<Boolean,FolBeliefSet,FolFormula>

public class SpassFolReasoner
extends FolReasoner

Invokes SPASS (http://www.mpi-inf.mpg.de/departments/automation-of-logic/software/spass-workbench/), an automated theorem prover for first-order logic, modal logic and description logics.

Author:

Anna Gessler

Field Summary

Fields inherited from class org.tweetyproject.logics.fol.reasoner.FolReasoner

defaultReasoner

Constructor Summary

Constructors

Constructor	Description
SpassFolReasoner(String binaryLocation)	Constructs a new instance pointing to a specific SPASS
SpassFolReasoner(String binaryLocation, Shell bash)	Constructs a new instance pointing to a specific SPASS Prover.

Method Summary

Modifier and Type	Method	Description
boolean	equivalent(FolBeliefSet kb, FolFormula a, FolFormula b)	This method determines whether two formulas are equivalent wrt.
boolean	isInstalled()	Checks whether the underlying solver or reasoning mechanism used by this reasoner is installed and available for use.
Boolean	query(FolBeliefSet kb, FolFormula query)	Queries the given belief base with the provided formula and returns a boolean result.
String	queryProof(FolBeliefSet kb, Formula query)	Determines the answer wrt.
void	setCmdOptions(String s)	Sets the command line options that will be used by SPASS when executing the query.

Methods inherited from class org.tweetyproject.logics.fol.reasoner.FolReasoner

getDefaultReasoner, setDefaultReasoner

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

SpassFolReasoner

public SpassFolReasoner(String binaryLocation,
 Shell bash)

Constructs a new instance pointing to a specific SPASS Prover.

Parameters:

binaryLocation - of the SPASS executable on the hard drive

bash - shell to run commands

SpassFolReasoner

public SpassFolReasoner(String binaryLocation)

Constructs a new instance pointing to a specific SPASS

Parameters:

binaryLocation - of the SPASS executable on the hard drive

Method Details

setCmdOptions

public void setCmdOptions(String s)

Sets the command line options that will be used by SPASS when executing the query.

Parameters:

s - a string containing the command line arguments

query

public Boolean query(FolBeliefSet kb,
 FolFormula query)

Description copied from interface: QualitativeReasoner

Queries the given belief base with the provided formula and returns a boolean result. The result indicates whether the formula is entailed or satisfied by the belief base according to the qualitative reasoning method implemented by the reasoner.

Specified by:

query in interface QualitativeReasoner<FolBeliefSet,FolFormula>

Specified by:

query in interface Reasoner<Boolean,FolBeliefSet,FolFormula>

Specified by:

query in class FolReasoner

Parameters:

kb - The belief base to be queried.

query - The formula for which the query is made.

Returns:

`TRUE` if the formula is entailed or satisfied by the belief base, `FALSE` otherwise.

queryProof

public String queryProof(FolBeliefSet kb,
 Formula query)

Determines the answer wrt. to the given query and returns the proof (if applicable). May decrease SPASS's performance, use query(FolBeliefSet,FolFormula) if only a yes/no result is needed.

Parameters:

kb - the knowledge base

query - a formula

Returns:

a string containing proof documentation

equivalent

public boolean equivalent(FolBeliefSet kb,
 FolFormula a,
 FolFormula b)

Description copied from class: FolReasoner

This method determines whether two formulas are equivalent wrt. to the given knowledge base.

Specified by:

equivalent in class FolReasoner

Parameters:

kb - the knowledge base

a - the first formula.

b - the second formula.

Returns:

the answer to the query.

isInstalled

public boolean isInstalled()

Description copied from interface: QualitativeReasoner

Checks whether the underlying solver or reasoning mechanism used by this reasoner is installed and available for use. This can be helpful when the reasoner depends on external tools or libraries for performing the reasoning tasks.

Returns:

`true` if the solver is installed and available, `false` otherwise.