Prompted by recent discussion on the Hat mailing list about the problems of type-defaulting, I have added two new proposals for this issue to the Haskell-prime wiki at: http://hackage.haskell.org/trac/haskell-prime/wiki/Defaulting The main new proposal is a different way of specifying defaults, which includes the name of the class being defaulted (thus allowing user-defined classes to play this game), but unlike the original proposal, permits only one type to be specified per class. The rules are therefore also simpler, whilst still (I believe) capturing the useful cases. A secondary proposal is to generalise defaults from having module-local scope, to global scope. This would allow library authors to capture the intended behaviour of their own classes and types, without bothering the library users. (Also, whilst removing module-local redefinition of defaults, the proposal would instead permit function-local re-definition.) I am less convinced of the need for this proposal, but in the spirit of exploring the design space, I thought it worth bringing up. Regards, Malcolm