Steve Dirickson writes:

> I've seen these concepts (binary reuse, code sharing, separation of code
> from data) mentioned several times in this thread, almost all in a context
> of either "OO claims to have invented this stuff" or "they are all that OO
> really is". They are clearly not new with OO, and are hardly identical
with
> OO. The defining, mandatory elements of the object model are:
>    Abstraction
>    Encapsulation
>    Modularity
>    Hierarchy

Not to pick nits (really!), but I believe the four are:

     Abstraction
     Encapsulation
     Polymorphism
     Inheritance

I can see how "hierarchy" could be used for "inheritance," but I fail
to see how "modularity" differs from "encapsulation;" it seems the former
would be a subset of the latter.  This explains why I don't see anything
like polymorphism in the first list.

--Glenn, who may just be short on understanding