[r-t] Parity

[Leigh Simpson]

> First. It is not necessary to sort the changes to
> derive the 'factorial 
> index'.

Thanks for this, it's all quite interesting. This sort
of stuff seems to be covered on this Wikipedia page:

http://en.wikipedia.org/wiki/Factoradic

which describes a "Factoradic" as a number providing a
lexicographic index for perms.

Leigh


      ___________________________________________________________ 
Yahoo! Mail is the world's favourite email. Don't settle for less, sign up for
your free account today http://uk.rd.yahoo.com/evt=44106/*http://uk.docs.yahoo.com/mail/winter07.html