de.learnlib.oracle.equivalence

Class CExFirstOracle<A extends Output<I,D>,I,D>

java.lang.Object

de.learnlib.oracle.equivalence.CExFirstOracle<A,I,D>

Type Parameters:

A - the automaton type

I - the input type

D - the output type

All Implemented Interfaces:

BlackBoxOracle<A,I,D>, EquivalenceOracle<A,I,D>, InclusionOracle<A,I,D>

Direct Known Subclasses:

DFACExFirstOracle, MealyCExFirstOracle

public class CExFirstOracle<A extends Output<I,D>,I,D>
extends Object
implements BlackBoxOracle<A,I,D>

The strategy of this black-box oracle is to first try out a property, to see if it can be disproved. If it can not be disproved it tries the same property to find a counter example to the hypothesis, before continuing with the next property.

This implementation may be used when refining a hypothesis is inexpensive compared to disproving propertyOracles.

Author:

Jeroen Meijer

See Also:

DisproveFirstOracle

Nested Class Summary

Nested classes/interfaces inherited from interface de.learnlib.api.oracle.BlackBoxOracle

BlackBoxOracle.DFABlackBoxOracle<I>, BlackBoxOracle.MealyBlackBoxOracle<I,O>

Nested classes/interfaces inherited from interface de.learnlib.api.oracle.InclusionOracle

InclusionOracle.DFAInclusionOracle<I>, InclusionOracle.MealyInclusionOracle<I,O>

Nested classes/interfaces inherited from interface de.learnlib.api.oracle.EquivalenceOracle

EquivalenceOracle.DFAEquivalenceOracle<I>, EquivalenceOracle.MealyEquivalenceOracle<I,O>

Constructor Summary

Constructors

Constructor and Description
CExFirstOracle()
CExFirstOracle(Collection<? extends PropertyOracle<I,? super A,?,D>> propertyOracles)
CExFirstOracle(PropertyOracle<I,A,?,D> propertyOracle)

Method Summary

Modifier and Type	Method and Description
@Nullable DefaultQuery<I,D>	findCounterExample(A hypothesis, Collection<? extends I> inputs) Searches for a counterexample disproving the subjected hypothesis.
List<PropertyOracle<I,? super A,?,D>>	getPropertyOracles() Returns the property oracles that this black-box oracle uses to evaluate properties.

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.learnlib.api.oracle.InclusionOracle

isCounterExample

Constructor Detail

CExFirstOracle

public CExFirstOracle()

CExFirstOracle

public CExFirstOracle(PropertyOracle<I,A,?,D> propertyOracle)

CExFirstOracle

public CExFirstOracle(Collection<? extends PropertyOracle<I,? super A,?,D>> propertyOracles)

Method Detail

getPropertyOracles

public List<PropertyOracle<I,? super A,?,D>> getPropertyOracles()

Description copied from interface: BlackBoxOracle

Returns the property oracles that this black-box oracle uses to evaluate properties.

Specified by:

getPropertyOracles in interface BlackBoxOracle<A extends Output<I,D>,I,D>

Returns:

the property oracles.

findCounterExample

public @Nullable DefaultQuery<I,D> findCounterExample(A hypothesis,
                                                      Collection<? extends I> inputs)

Description copied from interface: EquivalenceOracle

Searches for a counterexample disproving the subjected hypothesis. A counterexample is query which, when performed on the SUL, yields a different output than what was predicted by the hypothesis. If no counterexample could be found (this does not necessarily mean that none exists), null is returned.

Specified by:

findCounterExample in interface EquivalenceOracle<A extends Output<I,D>,I,D>

Parameters:

hypothesis - the conjecture

inputs - the set of inputs to consider, this should be a subset of the input alphabet of the provided hypothesis

Returns:

a query exposing different behavior, or null if no counterexample could be found. In case a non-null value is returned, the output field in the DefaultQuery contains the SUL output for the respective query.