[Haskell-cafe] Re: what is inverse of mzero and return?

[Jules Bean]

On 25 Jan 2005, at 12:22, Jules Bean wrote:

> The concrete example for [] is:
>
> concat . (map concat)
> should be the same (on all values of all types [a]) as
> concat . concat
>

..tiny correction, sorry. 'On all values of all types [[[a]]]'.