Hi, I am not sure if this is a known problem, but here's an example There is a module which imports Ix (from haskell98) and has some datatype deriving (Ix) This module does not compile with the following message: ================= Compiling Geometry ( ../../../home/dima/ext/workdirs/Fudgets/hsrc/utils/Geometry.hs ) yhc: -- during when renaming Error: Identifier Data.Ix._tupleRange used at 7:35-7:36 is not defined. Error: Identifier Data.Ix.inRange used at 7:35-7:36 is not defined. Error: Identifier Data.Ix.range used at 7:35-7:36 is not defined. Error: Type class Data.Ix.Ix used at 7:35-7:36 is not defined. Error: Identifier Data.Ix._tupleIndex used at 7:35-7:36 is not defined. Error: Identifier Data.Ix.index used at 7:35-7:36 is not defined. ================= line 7 is where deriving (...., Ix ) is located. If I import Data.Ix instead, everything compiles fine. The Ix module from haskell98 is: ================= module Ix ( Ix(range, index, inRange, rangeSize) ) where import Data.Ix ================= So, methods of the Ix class are not re-exported. I am pretty much OK importing Data.Ix (anyway, Fudgets code needs to be hierarchized, and I did something in this direction in the past), but this may be a problem in Yhc. Thanks. -- Dimitry Golubovsky Anywhere on the Web