Hi, I had some trouble getting syb-generics 2.9 to compile with ghc 6.5 (don't ask - I should probably be waiting for a stable release). I fixed the first problem by replacing a definition with in-line type info by splitting the type out, although I am not sure that I have done it right. Can anybody shed some light on this? Matthew ---------the error-------- Building syb-generics-2.9... [1 of 7] Compiling Data.Context ( Data/Context.hs, dist/build/Data/Context.o ) Data/Context.hs:48:9: A pattern type signature cannot bind scoped type variables `l' unless the pattern has a rigid type context In the pattern: l :: l () In the definition of `pairCtx': pairCtx (l :: l ()) (r :: r ()) = undefined :: PairCtx l r () --------original code------ pairCtx (l::l ()) (r::r ()) = undefined::PairCtx l r () --------my code------------- pairCtx :: l () -> r () -> PairCtx l r () pairCtx l r = undefined