ex:Animal a rdfs:Class;
          rdfs:subclassOf ex:Eukaryote;
          rdfs:comment "An animal".

ex:Plant a rdfs:Class;
          rdfs:subclassOf ex:Eukaryote;
          rdfs:comment "A plant".

ex:Mammal a rdfs:Class;
          rdfs:subclassOf ex:Animal;
          rdfs:comment "A mammal".
