I'm here again. I'm installed from hackage al dph-<something> packages but still I've problems using elemP and foldP (not found). If I import Data.Array.Parallel.PArr the compiler says: Could not find module `Data.Array.Parallel.PArr' it is a hidden module in the package `dph-par' it is a hidden module in the package `dph-seq' if I use before to build the command "ghc-pkg expose dph-par" and "ghc-pkg expose dph-seq" nothing changes. I'm using GHC 7.2.1 64-bit on MacOS X Lion (Xcode 4.1) Please, please, please, I really need help. Luca