Hi list,<div><br></div><div>I am using MonadSplit (from <a href="http://www.haskell.org/haskellwiki/New_monads/MonadSplit">http://www.haskell.org/haskellwiki/New_monads/MonadSplit</a> )  for a project and now I want to make a library out of it. This seems to be straightforward, but I got stuck when I tried to move miszero out of the class:</div>

<div><br></div><div>miszero :: m a -&gt; Bool </div><div><br></div><div>It tests if the provided monad instance is empty. My naive attempt was:</div><div><br></div><div>miszero :: (Eq (m a), MonadPlus m) =&gt; m a -&gt; Bool</div>

<div>miszero =  ( == mzero )</div><div><br></div><div>This works, but not correctly. It adds an Eq constraint that is unneeded. I would prefer to have something like:</div><div><br></div><div>miszero :: MonadPlus m =&gt; m a -&gt; Bool</div>

<div><br></div><div><br></div><div>Because I am not comparing the contents of the monad. I don&#39;t even touch it.  Is this possible to write?</div><div><br></div><div>with kind regards,</div><div><br></div><div>Edgar </div>