[Python-3000] sets in P3K?

[Paul Svensson]

> On 4/28/06, Greg Wilson <gvwilson at cs.utoronto.ca> wrote:
>> - introduce '@' as a prefix operator meaning 'freeze'.

Nice idea, but is it possible to be more radical ?
How about having all the existing literal syntaxes produce frozen containers,
using explicit calls to dict(), set(), list(), etc, to create mutable copies.
How much code would that break ?

 	/Paul