[Haskell-cafe] Proof of duality theorem of fold?
ekmett at gmail.com
Thu Mar 19 12:53:02 EDT 2009
I believe R J was consciously restricting himself to finite lists in the
2009/3/18 MigMit <miguelimo38 at yandex.ru>
> More interesting:
> foldl (flip const) whatever (repeat 1 ++ [1,2,3])
> Daniel Fischer wrote on 18.03.2009 15:17:
> Am Mittwoch, 18. März 2009 13:10 schrieb Daniel Fischer:
>>> Now prove the
>>> foldl g e (ys ++ zs) = foldl g (foldl g e ys) zs
>>> for all g, e, ys and zs of interest.
>>> (I don't see immediately under which conditions this identity could
>>> maybe there aren't any)
>> Of course, hit send and you immediately think of
>> foldl (flip const) whatever (undefined ++ [1,2,3])
>> Haskell-Cafe mailing list
>> Haskell-Cafe at haskell.org
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Haskell-Cafe