de.learnlib.api

Interface EquivalenceOracle<A,I,O>

Type Parameters:

A - automaton class this equivalence oracle works on

I - input symbol class

O - output class

All Known Subinterfaces:

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

public interface EquivalenceOracle<A,I,O>

An equivalence oracle, which checks hypothesis automata against the (possibly unknown) system under learning (SUL). Please note that equivalence oracles are implicitly connected to a SUL, there is no explicit references in terms of a MembershipOracle or such. However, this might be different in implementing classes. CAVEAT: Equivalence oracles serve as an abstraction to tackle the (generally undecidable) problem of black-box equivalence testing. The contract imposed by this interface is that results returned by the findCounterExample(Object, Collection) method are in fact counterexamples, BUT a null result signalling no counterexample was found does not mean that there can be none.

Author:

Maik Merten , Malte Isberner

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	EquivalenceOracle.DFAEquivalenceOracle<I>
static interface	EquivalenceOracle.MealyEquivalenceOracle<I,O>

Method Summary

Methods

Modifier and Type	Method and Description
DefaultQuery<I,O>	findCounterExample(A hypothesis, Collection<? extends I> inputs) Searches for a counterexample disproving the subjected hypothesis.

Method Detail

findCounterExample

DefaultQuery<I,O> findCounterExample(A hypothesis,
                                   Collection<? extends I> inputs)

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.

Parameters:

hypothesis - the conjecture

inputs - the set of inputs to consider

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.