{
{-# LANGUAGE BangPatterns #-}
module HelloWorld where

import Control.Monad.Error
}

itf H
  visit v1
    syn xs :: String

{
hello = sem hello : H monad Either String
          visit v1
            clause c1
              match True = False
              lhs.xs = "Hello World"

hello2 = sem hello2 : H monad Either String
           visit v1
             clause c3
               lhs.xs = "Booh!"
}