On Fri, Aug 14, 2009 at 8:13 AM, Kip Murray<[email protected]> wrote:
> The idea of verb realset is that
>
>    realset 3;1;4
> +-+-+-+
> |1|3|4|
> +-+-+-+
...
> The lesson seems to be that every verb that may need to compare sets to do its
> work needs &realset .  --I say "seems", I wouldn't be surprised if Raul has
> spotted a deeper problem I haven't noticed.  If so, Raul, will you amplify 
> your
> remark about equalset and the model's definition of "set"?

You have basically the right idea, here, but I would
characterize it as 3;1;4 is not a valid representation of
a set, but realset 3;1;4 is a set.

To see why, consider how you would test whether 3;1;4
is an element of a set of sets.

Put differently:

NB. A "set" is 0$<1 or a sorted list of unique boxes

(Note also that I left out "non-empty" because you do
not have a list of boxes if you have no boxes -- if you
did, you would not need to explicitly mention 0$<1).

-- 
Raul
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