owlontologyhermitreasoner

OWL HermiT debug satisfiability check


I am using HermiT v1.3.8.4 with OWLAPI v3.5.6 and run into an issue where reasoner.isSatisfiable(clazz) runs forever.

Is there a way to inspect what HermiT is doing, i.e., a way to get debug information?

My current setup looks roughly like this

OWLReasonerFactory reasonerFactory = new Reasoner.ReasonerFactory();
OWLReasonerConfiguration config;
if (this.verbose_output) {
    ConsoleProgressMonitor progressMonitor = new ConsoleProgressMonitor();
    config = new SimpleConfiguration(
        progressMonitor
    );
} else {
    config = new SimpleConfiguration();
}
OWLReasoner reasoner = reasonerFactory.createReasoner(this.ontology, config);

...

for (OWLClass c: this.ontology.getClassesInSignature(this.include_import_closure)) {
    if (!reasoner.isSatisfiable(c)) {  // This step takes forever
        continue;
    }

    ...
}

Solution

  • Not sure if this helps, but there are some classes that are related to debugging, although I never used those. You could try to use the following config option

    Configuration config=new Configuration();
    // Lets make HermiT open a debugger window from which we can control the 
    // further actions that HermiT performs. 
    // DEBUGGER_HISTORY_ON will cause HermiT to save the deriviation tree for 
    // each derived conclusion. 
    // DEBUGGER_NO_HISTORY will not save the derivation tree, so no causes for a 
    // clash can be given, but the memory requirement is smaller. 
    config.tableauMonitorType=TableauMonitorType.DEBUGGER_HISTORY_ON;
    // Now we can start and create the reasoner with the above created configuration.
    Reasoner hermit = new Reasoner(config,ontology);
    // This will open the debugger window at runtime and it should say:
    // Good morning Dr. Chandra. This is HAL. I'm ready for my first lesson.
    // Derivation history is on.
    // Reasoning task started: ABox satisfiability
    // > 
    // you can press 'c' to make HermiT continue with checking whether the ontology 
    // is consistent
    hermit.isSatisfiable(c); // for a class 'c'
    // HermiT should now have said 'Reasoning task finished: true' in the debugger window. 
    // Now, you can type 'showModel' to see all the assertions in the ABox that HermiT generated. 
    

    Otherwise, maybe the log level could help.