Hello! This is a little weird: Prelude> :m + Data.Array.Unboxed Prelude Data.Array.Unboxed> let f () = array (1, 5) [] :: UArray Int Int Prelude Data.Array.Unboxed> f () == f () False Are we giving away purity for efficiency? ;) If this behaviour is intended, maybe it should be documented? Maybe it would be a good idea to define default values for types which can be unboxed? Regards, Tom -- .signature: Too many levels of symbolic links