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   Date: Mon, 7 Jan 2002 13:29:26 -0500 (EST)
   From: Dan Weinreb <dlw@exceloncorp.com>
   To: sk@cs.brown.edu
   CC: ll1-discuss@ai.mit.edu
   Subject: Re: FP+OO
      Date: Mon, 7 Jan 2002 11:47:03 -0500 (EST)
      From: Shriram Krishnamurthi <sk@cs.brown.edu>
   					 (Example: people who say "OO is
      about data abstraction".  And what is ML about?  Plucking chickens?)
   Gee, I would say that OO is about data abstraction.  By which I would
   mean, the primary thing that the OO features of a language are
   especially good for is abstracting data.  I think that's true no
   matter what ML is about.  Now, if someone says "you can't do any kind
   of data abstraction unless you have OO stuff in your language", that
   would be different; but that's not what you said...

More precisely, one might well project the informal phrase
"is about" onto the more precise logical term "implies"
or "entails": If you're doing OO, then you are necessarily
doing data abstraction.

Then the question about ML seems to rest on the standard
fallacy of confusing a proposition with its converse.
Data abstraction does *not* necessarily imply OO.  The
statement "OO is about data abstraction" is then consistant
the possibility that both OO and ML imply data abstraction.
(It is also consistent with the possibility that ML is
chopped liver. :-)