In Bird-style you have to leave a blank before the code.

> fact :: Integer -> Integer
> fact 0 = 1
> fact n = n * fact (n-1)
 
And you have to leave a blank line after the code as well.  Unless
> 0 lines of blank space are left, this won't be highlighted as code.
    
> main = do
>   putStrLn "Hello World!"
