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

Ashley Yakeley ashley at semantic.org
Sat Jan 22 04:09:26 EST 2005

In article <41F211FB.3030706 at imperial.ac.uk>,
 Keean Schupke <k.schupke at imperial.ac.uk> wrote:

> This fits the above description, but I don't see how the following can 
> be true:
>     (mplus a b) >>= c = mplus (a >>= c) (b >>= c)

Try it (and my test code) with [], which is an instance of MonadPlus. 
mplus is defined as (++) for [].

Ashley Yakeley, Seattle WA

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