Hello all, I'm trying to write the simplest possible Haskell program, and I'm not getting anywhere. I have installed Hugs, GHC and GHCI. I want to run the following program: fac :: Integer -> Integer fac 0 = 1 fac n | n > 0 = n * fac (n-1) This is what I see: $ hugs Hugs.Base> fac :: Integer -> Integer ERROR - Undefined variable "fac" Hugs.Base> fac 0 = 1 ERROR - Syntax error in input (unexpected `=') $ ghci Prelude> fac :: Integer -> Integer <interactive>:1:0: Not in scope: `fac' Prelude> fac 0 = 1 <interactive>:1:6: parse error on input `=' $ # Write the program to fac.hs $ ghc fac.hs fac.hs:1:0: The main function `main' is not defined in module `Main' When checking the type of the main function `main' This is a real problem for Haskell. I expect that a lot of people try Haskell and give up because they can't even write the simplest function. It's hard not to be put off by this. I love the theory behind Haskell, but the practice of it seems to be a real problem. I hope someone will show me how to make this program work. Even better, I hope someone will fix the compilers and interpreters if they need fixing, or fix the documentation if that's what needs fixing. Best, Daniel. -- /\/`) http://oooauthors.org /\/_/ http://opendocumentfellowship.org /\/_/ \/_/ I am not over-weight, I am under-tall. /