arr   :: ArrowReadShow q => (a->b) -> q a b
(>>>) :: ArrowReadShow a => a b c -> a c d -> a b d
(<<<) :: ArrowReadShow a => a c d -> a b c -> a b d
first :: ArrowReadShow a => a b c -> a (b,d) (c,d)
second:: ArrowReadShow a => a b c -> a (d,b) (d,c)

(<**) :: ArrowReadShow a => a b c -> a d e -> a (b,d) (c,e)
(**>) :: ArrowReadShow a => a b c -> a d e -> a (b,d) (c,e)

(|||) :: ArrowReadShow a => a b c -> a d c -> a (Either b d) c
(+++) :: ArrowReadShow q => q a c -> q b d -> q (Either a b) (Either c d)

(<+>) :: ArrowReadShow q => q a b -> q a b -> q a b
(<|>) :: ArrowReadShow q => q a b -> q a c -> q a (Either b c)

readSymbol   :: ArrowReadShow q => String -> q a a
showSymbol   :: ArrowReadShow q => String -> q a a
mayReadParen :: ArrowReadShow q => Int -> q a b -> q a b
mayShowParen :: ArrowReadShow q => Int -> q a b -> q a b
setPrec      :: ArrowReadShow q => Int -> q a b -> q a b

high  :: Int
pair  :: a -> b -> (a,b)