Friends I propose that we support the GHC proposal "Declare Constraint is not apart from Typehttps://github.com/ghc-proposals/ghc-proposals/blob/rae/constraint-vs-type/p..." Currently GHC operates an uneasy compromise: * Constraint and Type are treated as distinct in the type checker (e.g. do not unify) * But they are treated as the same in Core I have spent ages in discussion with Richard and others for how to fix this wart. Really, they should be either * completely different (like Int and Bool), or * completely the same (like [Char] and String). But both these stances have problems, and nothing satisfying has emerged. So this proposal simply fixes the worst aspect (unsoundness) of the current setup. So I regard it as a way to stay explicitly non-committal, leaving the main question open. There are a couple of clarifications I'd like which I've put on the discussion thread. Simon