OWL API

Dear all, 

I seem to have an issue with swirl  rules.   I have a simple ontology with almost nothing in it, that is enough to test a rule. 
I load my ontology, create the rule and then do some reasoning but i don't see it's result. However i can see that the rule is in memory with the following instruction: 

 OWLObjectRenderer renderer = new DLSyntaxObjectRenderer(); 
        for (SWRLRule rule : ontology.getAxioms(AxiomType.SWRL_RULE)) { 
            System.out.println(renderer.render(rule)); 
        }

So the rule axiom is there, but when i try to obtain the result of its application i get nothing. 


however if i save the ontology (which now contain the rule). When re-execute the same code without this time re-receating the rule of course, my load rule from the file works perfectly. 



Is it a normal behavior? That is, that every time you create an in-memory rule, you must first save it in a file and then reload it to be able to use it for reasoning ?


Many thanks, 
Maatary