import Control.Monad
import System.FilePath
import System.Directory

wd1 <- getCurrentDirectory
setCurrentDirectory ".."
wd2 <- getCurrentDirectory
wd1_parent <- canonicalizePath (wd1 </> "..") 
wd2'       <- canonicalizePath wd2
unless (wd1_parent `equalFilePath` wd2') $ mapM_ print [wd1, wd1_parent, wd2, wd2']