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Re: Representing a set of value pairs?

From: Stan Devitt <jsdevitt@stratumtek.com>
Date: Sun, 20 Jul 2003 08:20:37 -0400
Message-ID: <3F1A8915.7010301@stratumtek.com>
To: "Roger L. Costello" <costello@mitre.org>
CC: www-math@w3.org

The construction

<set>
  <bvar>...</bvar>
  <condition>
     ...
  </condition>
  <list><ci>i</ci><ci>c</ci></list> 
</set>

is a sort of shorthand for constructing sets like

<set>
<list><ci>1</ci><ci>2.54</ci></list>
<list><ci>2</ci><ci>5.08</ci></list>
...
</set>

The last term in the constructor is an  "instance" of the set elements that
are to be constructed.  (I could have built a set of sets, but  I've already
seen one published map claiming that   1 km = 1.6 miles  :) )

The set is actually built by using the conditions to select valid pairs 
of bvar values and then for each such pair constructing an actual  
element ( in this case a list)

It corresponds in a very real sense  to the notation  
{   ( i , c )  |  conditions on i and c go here  }

Stan Devitt
StratumTek


Roger L. Costello wrote:

>Is the purpose of:
>
>   <list><ci>i</ci><ci>c</ci></list>
>
>to indicate "these are the set variables"? 
>
>Is there an advantage of using <list>...</list> rather than set, i.e.,
>
>   <set><ci>i</ci><ci>c</ci></set>
>
>Thanks!  /Roger
>
>  
>
Received on Sunday, 20 July 2003 08:18:33 GMT

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