Hi David, Thanks for responding. I'm out here at the hackage.haskell.org site and performed the search. I guess my first question here would be "what is missing"? Does this mean something is missing? I see it for a lot of the components (functions) of Data.List.Utils. Regards, CEO'Riley Charles E. O'Riley Jr. -----Original Message----- From: David McBride [mailto:toad3k@gmail.com] Sent: Tuesday, October 18, 2011 7:38 PM To: ceoriley@gmail.com Cc: beginners@haskell.org Subject: Re: [Haskell-beginners] Data-List-Utils Data.List.Utils is part of the missingh library. If your app can't find it, it is probably not installed. cabal install missingh. To find out where a random import comes from, go to hackage.haskell.org, click on hayoo, and search for "Data.List.Utils". The ambiguous module name is totally different and doesn't happen very often anymore. Monads-fd used to be an improved version of mtl, and it exported roughly the same interface, but monads-fd is now deprecated and shouldn't be used. Sometimes when you load a file it ends up choosing it anyways, because it has to choose something. You can avoid that by typing ghci -hide-package=monads-fd. Alternatively you can use ghc-pkg hide to hide it permanently, so that nothing tries to use that, that should work.