[Haskell-beginners] Error Loading Stdm.lhs in Haskell platform 2012

Dear Sir/Madam I Installed *Haskell Platform 2012.2.0.0 for Windowshttp://lambda.haskell.org/platform/download/2012.2.0.0/HaskellPlatform-2012.... *and try to load Stdm.lhs which is downloaded from http://www.dcs.gla.ac.uk/~jtod/discrete-mathematics/Stdm.lhs I have this error: stdm.lhs:1160:14: Parse error in pattern: n + 1 Failed, modules loaded: none. Is there anything I should do to make it right? Thank you. -- Iwan Awaludin