Jeff Thanks for your detailed reply. | In other words, the monomorphism restriction converts certain | let bindings to lambda bindings. But this approach pre-supposes that the monomorphism restriction takes priority over the "must generalise implicit parameters" rule. Once you make that supposition, then choice (B) follows. Note that choice (B) implies a loss of source-level beta reduction, which I regard as rather serious. But I rather think that the "must generalise implicit parameters" should take priority, and the monomorphism restriction should not. Then choice (C) follows. Indeed, many people think that the monomorphism restriction should go altogether, so (C) is a move in the right direction. So my take is still: let's adopt (C). Simon