Monadic Arithmetics

/* Stop >>= \a -> >>= \b insane! */

instance + (m a) | + a & Monad m
where
 (+) ma mb = ma >>= \a -> mb >>= \b -> return $! a + b

instance - (m a) | - a & Monad m
where
 (-) ma mb = ma >>= \a -> mb >>= \b -> return $! a - b

instance * (m a) | * a & Monad m
where
 (*) ma mb = ma >>= \a -> mb >>= \b -> return $! a * b

instance / (m a) | / a & Monad m
where
 (/) ma mb = ma >>= \a -> mb >>= \b -> return $! a / b

instance mod (m a) | mod a & Monad m
where
 (mod) ma mb = ma >>= \a -> mb >>= \b -> return $! a mod b

instance rem (m a) | rem a & Monad m
where
 (rem) ma mb = ma >>= \a -> mb >>= \b -> return $! a rem b

/* http://hpaste.org/10673 */