Monad classes using type families, with instances for various monad transformers, inspired by the paper /Functional Programming with Overloading and Higher-Order Polymorphism/, by Mark P Jones, in Advanced School of Functional Programming, 1995 (http://web.cecs.pdx.edu/~mpj/pubs/springschool.html). After uninstalling, run this command to unregister the package from the ghc package database: ghc-pkg recache