Konclude crashes on example SPARQL

Hi there, I am experiencing the following problem: I started Konclude 0.7 using the command ./Konclude.bat sparqlserver -p 8080. Then I tried to send the following query from your SPARQL examples:

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX ub: <http://www.lehigh.edu/~zhp2/2004/0401/univ-bench.owl#>
SELECT ?X
WHERE
{ 
    ?X rdf:type _:c1 . _:c1 rdf:type owl:Class .
    _:c1 owl:intersectionOf _:c2 .
    _:c2 rdf:first ub:GraduateStudent .
    _:c2 rdf:rest _:c3 .
    _:c3 rdf:first ub:UndergraduateStudent .
    _:c3 rdf:rest rdf:nil .
}

However, Konclude crashes unexpectedly and without explanation. This is the log:

Starting Konclude ...
{info} 16:02:36:912 >> Konclude - Uni Ulm Parallel Reasoner
{info} 16:02:36:912 >> Reasoner for the SROIQV(D) Description Logic, 64-bit, Version v0.7.0-1135 - 91b3e331 (Mar 16 2021)

{info} 16:02:36:927 >> Initializing reasoner. Creating calculation context.
{info} 16:02:36:927 >> Reasoner initialized with 1 processing unit(s).
{info} 16:02:36:938 >> Listening on port '8080'
{info} 16:02:54:342 >> Preprocessing ontology 'http://Konclude.com/Ontologies/UnnamedOntologies/0/224382d5-2d7b-4cd0-b25e-af98e3cd2793/'.
{info} 16:02:54:344 >> Finished preprocessing in 2 ms for ontology 'http://Konclude.com/Ontologies/UnnamedOntologies/0/224382d5-2d7b-4cd0-b25e-af98e3cd2793/'.
{info} 16:02:54:344 >> Precomputing ontology 'http://Konclude.com/Ontologies/UnnamedOntologies/0/224382d5-2d7b-4cd0-b25e-af98e3cd2793/', expressiveness 'ALI+'.
{info} 16:02:54:346 >> Finished precomputing in 2 ms for ontology 'http://Konclude.com/Ontologies/UnnamedOntologies/0/224382d5-2d7b-4cd0-b25e-af98e3cd2793/'.
{info} 16:02:54:346 >> Initializing complex query answering for ontology 'http://Konclude.com/Ontologies/UnnamedOntologies/0/224382d5-2d7b-4cd0-b25e-af98e3cd2793/', expressiveness 'ALI+'.
{info} 16:02:54:347 >> Preparing query answering handler.
{info} 16:02:54:347 >> Query answering hanlder prepared.

Cheers! Robin

Thanks for the report! I can confirm that Konclude is crashing if you send this query and no data is loaded (which should obviously not be the case). If some data is loaded (e.g., LUBM), then it seems to work fine, e.g., the following query does seem to be processed as expected:

LOAD <file:Tests/lubm-univ-bench.owl.xml>
LOAD <file:Tests/lubm-univ-bench-data-1.ttl>

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX ub: <http://www.lehigh.edu/~zhp2/2004/0401/univ-bench.owl#>
SELECT ?X
WHERE
{ 
 ?X rdf:type _:c1 . _:c1 rdf:type owl:Class .
 _:c1 owl:intersectionOf _:c2 .
 _:c2 rdf:first ub:GraduateStudent .
 _:c2 rdf:rest _:c3 .
 _:c3 rdf:first ub:UndergraduateStudent .
 _:c3 rdf:rest rdf:nil .
}

I leave the issue open until the crash is fixed, but it may not have the highest priority at the moment.

konclude / Konclude

Konclude crashes on example SPARQL #21