Cannot get instances of a class from kernel

Hi,

I am struggling to get the instances of a given class. Here is a simple example, in C (see attached file):

int main ( void )
{
    // create kernel
    fact_reasoning_kernel* k = fact_reasoning_kernel_new();

    // create class C
    fact_concept_expression* c = fact_concept(k,"C");

    // create I, an instance of C
    fact_individual_expression* i = fact_individual(k,"I");
    fact_instance_of ( k, i, c);

    fact_actor* actor = fact_concept_actor_new();

    fact_get_instances ( k, c, &actor);
    print2Darray(fact_get_elements_2d(actor));

    fact_actor_free(actor);
    // we done so let's free memory
    fact_reasoning_kernel_free(k);
    return 0;
}

The output is the following (I've enabled verbosity):

#!

FaCT++.Kernel: Reasoner for the SROIQ(D) Description Logic, 64-bit
Copyright (C) Dmitry Tsarkov, 2002-2015. Version 1.6.4 (23 August 2015)
(instance I C)
Preprocessing... done in 0 seconds
Consistency checking... done in 0 seconds
Processing query... done in 0 seconds
[
[C ]
[BOTTOM ]
]

I expect I to be present, since it is an instance of C. However I only seem to get classes/concepts back, which is surprising. I am not expecting any ConceptExprs, rather only IndividualExprs. It looks like the kernel is returning the subconcepts/subclasses rather than the instances. Both functions getSubConcepts and getInstances look very similar. I can't figure out where getInstances effectively differs. However my understanding of Fact++'s internals is non-existent.

The workaround I have found so far is to go through my instances one-by-one and ask isInstance on it. However I suspect that the kernel can give me the same result somehow. This was tested against latest master.

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