Prelude.List.(++) : List a -> List a -> List a Prelude.Strings.(++) : String -> String -> String a is not an implicit argument of Prelude.Interfaces./ Usage is :doc <functionname> Usage is :wc <functionname> Usage is :printdef <functionname> pat {ty504} : Type toplevel.u. pat {__class505} : Prelude.Interfaces.Fractional {ty504}. Prelude.Interfaces./ {ty504} {__class505} : pty {ty504} : Type toplevel.u. pty {__class505} : Prelude.Interfaces.Fractional {ty504}. {ty504} -> {ty504} -> {ty504} (input):1:1: error: expected: ":", dependent type signature, end of input /<EOF> ^ (input):1:1: error: expected: ":", dependent type signature, end of input ++<EOF> ^ Can't find implementation for Fractional ty