- From: Stan Devitt <jsdevitt@stratumtek.com>
- Date: Sun, 20 Jul 2003 08:20:37 -0400
- 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 UTC