Dear Jens, the problem is quite simple, but alas, the error message leaves much to be disired: standalone Haskell program must contain a `main' function in the `Main' module (thus the missing Main_main_closure reference). Furthermore, this `main' function must have the type signature `IO ()' (or was that finally changed to `IO a'?). In essence, you have just given a function (`add'), but not specified how your program should interact with the world. To do this you could add a module like: module Main where import Add main = print (add 42 1729) and compile with ghc -c Add.hs (file and module name must be identical) ghc -c Main.hs ghc -o Main Main.o Add.o Best regards, Tommy [EMAIL PROTECTED] wrote/a ecrit/skrev: > Dear Sir or Madam > > I have written this small simple program > > module Add where > add :: Int -> Int -> Int > add x1 x2 x1 + x2 > > I have create an object file with the command % ghc -c additon.hs > Now I will create an executable file. > What I have to do? > > The command % ghc -o addition addition.o give me following failure message: > > /usr/lib/ghc-4.02/libHS.a(PrelMain__8.0)(.text+0x2a) > undefined reference to 'Main_main_closure' > /usr/lib/ghc-4.02/libHS.a(PrelMain__8.0)(.data+0xc) > undefined reference to 'Main_main_closure' > > If you can help me, please contact me under: > > [EMAIL PROTECTED] > > I use a Red Hat 5.1 system and GHC 4.02 . > > Yours sincerely > > Jens Fiedler
