Re: Quantified Expressions: "some"

[stefan-lucks@see-the.signature]

On Wed, 17 Nov 2010, Georg Bauhaus wrote:

> AI05-0176 explains two new expressions,
> 
>  (for all X in domain | P (X))
> 
> and
> 
>  (for some X in domain | P (X))

As a keyword-reuising alternative for "for some", Geor proposed

>  (for when X in domain | P (X))

This is really ill-readable, IMHO. As others in this thread have pointed
out, this may be read as "all", actually.

If you really really really wanted to avoid "some", use Mathematics:

    P holds for some X    <=>   not (not P holds for all X).

Thus, the expression

   (for some X in domain | P(X))

could be rephrased as

   (not (for all X in domain | not P(X)))

without any need for the word "some".

But honestly, I prefer to write "some" over using "not" twice.

Stefan


-- 
------ Stefan Lucks   --  Bauhaus-University Weimar  --   Germany  ------
               Stefan dot Lucks at uni minus weimar dot de
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