[Haskell-cafe] Referring to Prelude.(++)

I'd like to redefine (++) so that it works on a more general class of "lists" (ListOf a). To do this, I found that I can import the Prelude hiding the definition of (++). Then I want to make [] an instance of ListOf, and have the (++) function call the built-in Prelude.(++). My problem is that I can't figure out how to call the built-in function. Just using "Prelude.(++)" doesn't seem to work in the way that "Prelude.foldl" would (for example). Any ideas? Terry