interface Source_Position where
make :: Int -> Int -> Source_Position
	{-# ARITY make = 2 #-}
next_line :: Source_Position -> Source_Position
	{-# ARITY next_line = 1 #-}
shift_column :: Source_Position -> Int -> Source_Position
	{-# ARITY shift_column = 2 #-}
show_pos :: Source_Position -> [Char] -> [Char]
	{-# ARITY show_pos = 1 #-}
start :: Source_Position
	{-# ARITY start = 0 #-}
data Source_Position = Source_Position Int Int
instance Text Source_Position
	{-# ARITY readsPrec = 0 #-}
	{-# ARITY showsPrec = 2 #-}
	{-# ARITY readList = 0 #-}
	{-# ARITY showList = 0 #-}