RE: [xml-dev] Subtyping in XML

From
Bullard, Claude L (Len) <>
To
'John Cowan' <>
Date
2002-09-09T21:23:26Z
ID
<2C61CCE8A870D211A523080009B94E430752B91D@HQ5>
Thread
RE: [xml-dev] Subtyping in XML
Cantor The Mad.  Back to the denumerability thing 
and quantum foaming at the mouth...

Ok.  Still, he said 

"types first and formost define a concept of membership.
Such definitions must be formal and unambiguous."

So are you saying "unambiguous" means countable?

len

-----Original Message-----
From: John Cowan [mailto:]

"Bullard, Claude L (Len)" scripsit:

> Doesn't that make type synonymous with set?

No.  Types have to be specifiable: there are only countably many types,
but there are uncountably many sets, indeed $2^\aleph_0$ of them.
An easy way to achieve this is to require that types have names.