[Haskell-cafe] Set of reals...?

Hi all, I'm new to this list, as well as to haskell, so this question probably has "newbie" written all over it. I'm thinking of a way to represent a set of reals, say the reals between 0.0 and 1.0. Right now I am just using a pair of Float to represent the lower and upper bounds of the set, but i have this dark throbbing feeling that there should be a more haskellish way to do this, using laziness. List comprehensions are out it seems, because they increment with integer steps... (obviously). In other words, 0.5 `inSet` (Set [0.0..1.0]) returns False. I'm sure someone must have hit this problem before me and found a way around it. any suggestions greatly appreciated, regards, stijn.