title: UML: disjoint vs. overlapping academic scrap?
body: <p>It's not a real programming (coding) problem, sorry for that (but design comes first).</p>
  
  <p>I don't understand the difference between <code>disjoint</code> and <code>overlapping</code>. It occurs in several books, has a relation to <code>OCL</code>, which is considered part of <code>UML</code>, but the latest OCL specification by OMG no longer mentions these terms; therefore, it appears somewhat ill-defined to me. I would greatly appreciate if someone could clarify what's behind this. Is it simply multiple-inheritance of the same super-class?</p>