[Bug 3244] Sets of lists

http://www.w3.org/Bugs/Public/show_bug.cgi?id=3244





------- Comment #1 from davep@iit.edu  2006-05-20 01:18 -------
(In reply to comment #0)
> QT approved comment:
> 
> In 3.2.1, the initial definition correctly refers to "the set of all lists",
> while section 3.2.1.1 incorrectly refers to "all sets of lists". [The union of
> all sets of lists is a powerset.] 

The union of all sets of lists is a set of lists, which is what we want.  To
coin some in-line notation (read ';' as "subject to the condition"), in 3.2.1
we specified:

    ( U x ; (x a primitive datatype) (value space of x) ) u { x ; x is a list }

or equivalently:

    ( U x ; (x is a primitive datatype's value space ) x u { x ; x is a list }

In 3.2.1.1 we probably were thinking of:

    U x ; (x is a primitive datatype's value space or x is a set of lists) x

The comma changed the meaning, and in any case we might make the two parallel
or perhaps remove one.

Received on Saturday, 20 May 2006 01:18:38 UTC