[cap-talk] "Composite", was "Same" key

[David Hopwood]

Charles Landau wrote:
> At 1:15 AM +0000 2/15/07, David Hopwood wrote:
> 
>> I wrote:
>>  > Charles Landau wrote:
>>  >>              1                          >1                 >=1
>>
>>>> 1 (MarkM)   Object                   Composite           ?
>>>
>>> The "?" is "Composite".
> 
> I couldn't find a formal definition of "composite" in MarkM's thesis, so
> perhaps he can clarify. But it seems to defy common English to say a
> single atomic object is also a "composite".

In section 6.2:

# For compactness of description, we often aggregate a set of objects into
# a composite.

So a composite is a set of objects, which may be a singleton set. Nothing
else in section 6.2 contradicts a single object being a special case of
a composite. More to the point, it is useful to view it as such, because
clients of a composite cannot necessarily tell whether it is made up of
more than one object.

>>  >>3 (Landau)  Atomic object            Composite object    Object
>>
>> An abstraction with two objects such that one is an interface subset
>> of the other, is an instance of the ">1" column.
> 
> Yes.
> 
>> I thought that part of
>> your argument was that you didn't want to call that "composite", since
>> it is not constructed by composition, narrowly defined.
> 
> No. This example is clearly a composite.

Then I had obviously misunderstood your argument against using "composite"
(i.e. MarkM's definitions). The remaining argument about "defying common
English" seems to me to be overstated and not particularly important.
Very often the choice of a technical term is well-motivated by ordinary
English uses in the common case, but less well-motivated for special cases.
You just have to learn that the special cases are included.

-- 
David Hopwood <david.nospam.hopwood at blueyonder.co.uk>