Re: Nested Relations / RVAs / NFNF

tonyisyourpal_at_netscape.net (Tony Douglas) wrote:

>"Mikito Harakiri" <mikharakiri_at_iahu.com> wrote in message news:<rrChd.24$J%6.180_at_news.oracle.com>...

[snip]

>> I disagree. Civilization progress so far has been along generalizing
>> concrete objects into abstract concepts. This is how we've got the concept
>> of number. We manipulate numbers without being forced to constantly
>> typecheck:
>>
>> 2 cows + 3 bulls = a herd of 5

>Yes, but what is the type of 2 cows + 3 cats ? Also, what are the

     Whatever you define it as. It would depend on the type of each of the operands. With collective nouns, it could get tricky:

          1 herd + 1 herd = 1 herd

>types actually being handled here ? Integers, or cows and bulls ? Is
>it legal to divide cows by bulls ? (Multiplication is obviously
>possible ;) And we probably do type-check these kinds of things, but
>it's such a low level thing we hardly notice it, until the types are
>different (e.g. work out in your head what 87.2 kilograms minus 2
>pounds 3 ounces is).

     About 86.2 Kg. 2 pounds, 3 ounces is a good approximation to 1 Kg.

     For real fun, which weighs more, 1 oz. feathers or 1 oz. gold?

[snip]

>Indeed; if you have something physically represented by integers, and
>division is permissible for the type you're modelling, then you can go
>ahead and use integer division, under the covers. But division (or
>multiplication, or square, or mod, or whatever) may not be permissible
>operations for your new type, so shouldn't be available.

     That would depend on the units. A scalar amount ought to be just fine:

          5 scalar X 16 cats = 80 cats
          5 feet X 16 cats = ERROR

Sincerely,

Gene Wirchenko

Computerese Irregular Verb Conjugation:

     I have preferences.
     You have biases.
     He/She has prejudices.