RE: Proposed simplification of datatype expressions

> From: pat hayes [mailto:phayes@ai.uwf.edu] 
>
> >"people who have at least three values for property x."
> >
> >where x is a data valued property. I, too, struggle to think 
> of an example
> >where one would actually want to use such a construct (but am open to
> >suggestion)....
> 
> People who own three or more homes, people with at least three 
> sources of income, people with at least three children, people with 
> with at least three nationalities, people who have travelled to more 
> than three foreign nations during the last six months,....

All good examples of cardinality contraints to objects; I have to say
that I'm not convinced that any of the following are naturally
datatypes:

- homes
- sources of income
- children
- nationalities
- travel to a given nation during a date range

Nationality, in my view, comes closest; but why is this better as a
datatype than an object?

		- Peter