Who knows, please, where there are explained hierarchical module names? Is this a matter of Haskell-98 or of GHC ? I looked into both of them (and also a bit into libraries@haskell.org) but could not find a basic explanation of the point, somehow missed. Suppose that my user package called dumatel exports a module of kind --------------------------- module List (union) where import Data.List import qualified List union xs ys = f (Data.List.union xs (List.union ys ys)) f = ... --------------------------- First, the module name List conflicts with such of the base package of GHC. So, I change this to --------------------------- module Dumatel.List (union) where where import Data.List import qualified List union xs ys = f (Data.List.union xs (List.union ys ys)) f = ... --------------------------- Second, -v key in ghc --make shows that GHC decides to search for the module Dumatel.List only in the files ./Dumatel/*.hs and ./Dumatel/*.lhs So, I create a directory and put the above module to the file ./Dumatel/List.hs Does this all mean "to use hierarchical module names"? Does the module name "Dumatel.List" agree with Haskell-98 ? What is the currently most convenient way to resolve module name clashes between the packages? Is this the above arrangement with subdirectories and module names with dots (and with "qualified-as" import) ? Thank you in advance for explanation. Regards, ----------------- Serge Mechveliani mechvel@botik.ru