> Try this instead: > > > instance Foo (Bar RealWorld) where > > foo = stToIO . getFirst > > It should work OK, since it doesn't have the free type variable. Yes, this is what I have. But this kind of makes the fact that I'm in ST useless, since afaik (ST RealWorld) is basically the same as IO, so there's no reason for me to stay in the ST realm... - Hal