On Mon, Feb 3, 2014 at 5:51 PM, Dan Burton <danburton.email@gmail.com> wrote:
Indeed this issue is not limited merely to multiple failure values.

    >>> runMaybeT $ lift (putStrLn "effect") >> mzero
    effect
    >>> runMaybeT mzero

So you're right. This law is being violated 

I thought it was fairly well known that IO violates one of the monad laws, in a way that would lead to this?

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