+interface Oberon_Id where
+from_string :: [Char] -> Oberon_Id
+ {-# ARITY from_string = 1 #-}
+to_string :: Oberon_Id -> [Char]
+ {-# ARITY to_string = 1 #-}
+data Oberon_Id
+instance Eq Oberon_Id
+ {-# ARITY (==) = 2 #-}
+ {-# ARITY (/=) = 0 #-}
+instance Text Oberon_Id
+ {-# ARITY readsPrec = 0 #-}
+ {-# ARITY showsPrec = 2 #-}
+ {-# ARITY readList = 0 #-}
+ {-# ARITY showList = 0 #-}
+