title: min cardinality not working as expected in Protege
body: <p>I'm a beginner in Protege / OWL and I'm having trouble understanding why max cardinality is working and min cardinality is not. 
  I tried Hermit Pellet and Fact as reasoners. I know about the Open World Assumtion, but this seems not logical to me.</p>
  
  <p>I want to express that there must be at least 2 Persons in a Marriage event.</p>
  
  <blockquote>
    <p>Class: MarriageEvent</p>
    
    <p>EquivalentTo:</p>
  </blockquote>
  
  <p><strong>This works:</strong> 
  <code>MarriageEvent and is_event_of max 2 Person</code></p>
  
  <p><strong>And this not:</strong>
  <code>MarriageEvent and is_event_of min 2 Person</code></p>
  
  <p>All individuals are declared as different individuals.</p>
  
  <p>My ontology:</p>
  
  <pre><code> &lt;?xml version="1.0"?&gt;
   &lt;Ontology xmlns="http://www.w3.org/2002/07/owl#"
   xml:base="http://www.semanticweb.org/anato/ontologies/2017/7/untitled-ontology-184"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:xml="http://www.w3.org/XML/1998/namespace"
   xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
   xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
   ontologyIRI="http://www.semanticweb.org/anato/ontologies/2017/7/untitled-ontology-184"&gt;
  &lt;Prefix name="owl" IRI="http://www.w3.org/2002/07/owl#"/&gt;
  &lt;Prefix name="rdf" IRI="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/&gt;
  &lt;Prefix name="xml" IRI="http://www.w3.org/XML/1998/namespace"/&gt;
  &lt;Prefix name="xsd" IRI="http://www.w3.org/2001/XMLSchema#"/&gt;
  &lt;Prefix name="rdfs" IRI="http://www.w3.org/2000/01/rdf-schema#"/&gt;
  &lt;Declaration&gt;
      &lt;NamedIndividual IRI="#Peter"/&gt;
  &lt;/Declaration&gt;
  &lt;Declaration&gt;
      &lt;NamedIndividual IRI="#Julia"/&gt;
  &lt;/Declaration&gt;
  &lt;Declaration&gt;
      &lt;ObjectProperty IRI="#is_event_of"/&gt;
  &lt;/Declaration&gt;
  &lt;Declaration&gt;
      &lt;NamedIndividual IRI="#Max"/&gt;
  &lt;/Declaration&gt;
  &lt;Declaration&gt;
      &lt;Class IRI="#Person"/&gt;
  &lt;/Declaration&gt;
  &lt;Declaration&gt;
      &lt;NamedIndividual IRI="#Event_Marriage"/&gt;
  &lt;/Declaration&gt;
  &lt;Declaration&gt;
      &lt;Class IRI="#MarriageEvent"/&gt;
  &lt;/Declaration&gt;
  &lt;EquivalentClasses&gt;
      &lt;Class IRI="#MarriageEvent"/&gt;
      &lt;ObjectIntersectionOf&gt;
          &lt;Class IRI="#MarriageEvent"/&gt;
          &lt;ObjectMinCardinality cardinality="2"&gt;
              &lt;ObjectProperty IRI="#is_event_of"/&gt;
              &lt;Class IRI="#Person"/&gt;
          &lt;/ObjectMinCardinality&gt;
      &lt;/ObjectIntersectionOf&gt;
  &lt;/EquivalentClasses&gt;
  &lt;EquivalentClasses&gt;
      &lt;Class IRI="#MarriageEvent"/&gt;
      &lt;ObjectIntersectionOf&gt;
          &lt;Class IRI="#MarriageEvent"/&gt;
          &lt;ObjectMaxCardinality cardinality="2"&gt;
              &lt;ObjectProperty IRI="#is_event_of"/&gt;
              &lt;Class IRI="#Person"/&gt;
          &lt;/ObjectMaxCardinality&gt;
      &lt;/ObjectIntersectionOf&gt;
  &lt;/EquivalentClasses&gt;
  &lt;DisjointClasses&gt;
      &lt;Class IRI="#MarriageEvent"/&gt;
      &lt;Class IRI="#Person"/&gt;
  &lt;/DisjointClasses&gt;
  &lt;ClassAssertion&gt;
      &lt;Class IRI="#MarriageEvent"/&gt;
      &lt;NamedIndividual IRI="#Event_Marriage"/&gt;
  &lt;/ClassAssertion&gt;
  &lt;ClassAssertion&gt;
      &lt;Class IRI="#Person"/&gt;
      &lt;NamedIndividual IRI="#Julia"/&gt;
  &lt;/ClassAssertion&gt;
  &lt;ClassAssertion&gt;
      &lt;Class IRI="#Person"/&gt;
      &lt;NamedIndividual IRI="#Max"/&gt;
  &lt;/ClassAssertion&gt;
  &lt;ClassAssertion&gt;
      &lt;Class IRI="#Person"/&gt;
      &lt;NamedIndividual IRI="#Peter"/&gt;
  &lt;/ClassAssertion&gt;
  &lt;DifferentIndividuals&gt;
      &lt;NamedIndividual IRI="#Event_Marriage"/&gt;
      &lt;NamedIndividual IRI="#Julia"/&gt;
      &lt;NamedIndividual IRI="#Max"/&gt;
      &lt;NamedIndividual IRI="#Peter"/&gt;
  &lt;/DifferentIndividuals&gt;
  &lt;ObjectPropertyAssertion&gt;
      &lt;ObjectProperty IRI="#is_event_of"/&gt;
      &lt;NamedIndividual IRI="#Event_Marriage"/&gt;
      &lt;NamedIndividual IRI="#Julia"/&gt;
  &lt;/ObjectPropertyAssertion&gt;
  &lt;ObjectPropertyAssertion&gt;
      &lt;ObjectProperty IRI="#is_event_of"/&gt;
      &lt;NamedIndividual IRI="#Event_Marriage"/&gt;
      &lt;NamedIndividual IRI="#Peter"/&gt;
  &lt;/ObjectPropertyAssertion&gt;
  &lt;SubObjectPropertyOf&gt;
      &lt;ObjectProperty IRI="#is_event_of"/&gt;
      &lt;ObjectProperty abbreviatedIRI="owl:topObjectProperty"/&gt;
  &lt;/SubObjectPropertyOf&gt;
  &lt;IrreflexiveObjectProperty&gt;
      &lt;ObjectProperty IRI="#is_event_of"/&gt;
  &lt;/IrreflexiveObjectProperty&gt;
  &lt;ObjectPropertyDomain&gt;
      &lt;ObjectProperty IRI="#is_event_of"/&gt;
      &lt;Class IRI="#MarriageEvent"/&gt;
  &lt;/ObjectPropertyDomain&gt;
  &lt;ObjectPropertyRange&gt;
      &lt;ObjectProperty IRI="#is_event_of"/&gt;
      &lt;Class IRI="#Person"/&gt;
  &lt;/ObjectPropertyRange&gt;
  &lt;/Ontology&gt;
  
  &lt;!-- Generated by the OWL API (version 4.2.8.20170104-2310) https://github.com/owlcs/owlapi --&gt;
  </code></pre>