applescript filters and style ids

[Michael Esveldt]

Applescript question. The following returns all visible rows that have
the first named style of the first selected row:

		set theStyle to id of first named style of style of first selected row
		return  (every row whose visible is true and (id of named styles of
style of it contains theStyle))

But why is the id portion required? Removing it causes those lines to
cease functioning (though it doesn't produce an error). It's easy to
use ids, of course, but it's a bit bulky and I can't see why I can't
"directly" compare named styles.

Thanks,
Michael