writeAndLatexFile file content = do
  writeFile (file ++ ".tex") content
  system ("latex" +++ file ++ ".tex >& /dev/null ; xdvi" +++ file ++ ".dvi &")
  return ()
writeAndLatexFile file content = do
  writeFile (file ++ ".tex") content
  system ("latex" +++ file ++ ".tex >& /dev/null ; xdvi" +++ file ++ ".dvi &")
  return ()
writeAndLatexFile file content = do
  writeFile (file ++ ".tex") content
  system ("latex" +++ file ++ ".tex >& /dev/null ; xdvi" +++ file ++ ".dvi &")
  return ()