Mailing List Archive: 49091 messages

## [REBOL] Re: Best Language

### From: joel:neely:fedex at: 11-Dec-2002 13:54

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Hi, Reichart,

Interesting questions!

Reichart wrote:
> What representational system, besides English, is good at expressing
> the following three (characteristic) statements, and how would these
> statements be represented in that system?
>
>     1) L is a list of Foobles.
>

One of the following

L :: [Fooble]
or
L = {f | f (- Foobles}

(where the "(-" is really a lowercase epsilon!)

>     2) L is a list of Glorps of Foobles.
>        (Assume G(f) maps Foobles to Glorps)
>

This one is a little harder, because there are two different issues,
in my mental model:

L :: [Glorp]
or
L = {g | g (- Glorps}

express the idea that L is a list of Glorps (without worrying about
where they came from).  If I *need* to worry about the Foobles used
to "manufacture" the specific Glorps in question, I'd probably write

L = {G(f) | f (- Foobles}

>     3) L is a list of Foobles such that each Fooble is H() of
>        the one before it.  (Where H(f) is a function mapping
>        Foobles to Foobles.)
>

As the construction becomes more complex, I tend to fall back on more
and more formal notation.  If I want to focus on the pairwise element
relationships, I might write

(A i,j : 0 < i < N : L.i = H.L.(i-1))

or, if I think for a few seconds about the implications of the above,

L.i = H^i.f0 | f0 (- Foobles

or, if I just want a high-level description,

L contains the iterates of H over f0

depending on the need of the moment.

-jn-

--
----------------------------------------------------------------------
Joel Neely            joelDOTneelyATfedexDOTcom           901-263-4446
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