$ ghci ___ ___ _ / _ \ /\ /\/ __(_) / /_\// /_/ / / | | GHC Interactive, version 6.2.1, for Haskell 98. / /_\\/ __ / /___| | http://www.haskell.org/ghc/ \____/\/ /_/\____/|_| Type :? for help. Loading package base ... linking ... done. Prelude> :t (+) (+) :: forall a. (Num a) => a -> a -> a Prelude> 1 + 1 2 Prelude> 1.0 + 1.0 2.0 Prelude> :module +Ratio Prelude Ratio> 1%2 + 1%3 5 % 6