a more or less simple question concerning the GeneralizationSet. Let's
consider:
class Super
class Sub1 extends Super
class Sub2 extends Super
Concerning the GeneralizationSet (GS) mechanism, the spec mentioned,
that a GS will covering, if instances of Sub1 are also an instance of
Sub2. So far so good, but...
IMHO, this instance relationsship deals with the UML-internal instance
specification mechanism, am i right? In Java, for example, any check
like (sub1 instanceof sub2) will fail, because there are not directly
compatible (only via an upcast).
But in UML it seems possible, that an instance of a subclass can also be
an instance of any other corelating subclass of this GS, since any
instance specification can point to several classifiers.