the relations and properties as holding of temporal 
&gt; 'slices' of the things, or does one refer to the changes explicitly? 

   Do you think it is impossible to create one set of defining concepts
that will allow a user to assert facts using any one of these methods,
as seems best suited for the task?  
    It can be anticipated that different users might well create
different ontologies in which the axioms are contradictory.   This is 
unavoidable with any defining vocabulary -- one user says "yes" whe