Re: SQL (was: Why using "Group By")

"--CELKO--" <71062.1056_at_compuserve.com> wrote in message news:c0d87ec0.0303141635.612e1522_at_posting.google.com...
> >>Do you have an example problem requiring recursion for which
> transitive closure provides no solution? <<
>
> The Ackermann function, for one:
>
> A(0, m) = m+1
> A(n+1, 0) = A(n, 1)
> A(n+1, m+1) = A(n, A(n+1, m))

Aha, I remember this one

http://www.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&selm=bdf69bdf.02010 70553.1dcb8788%40posting.google.com

but could anybody provide more substantial reference? Received on Sat Mar 15 2003 - 02:18:09 CET