from my notes 
Monad
Functor -> Applicative -> Monad
class Applicative m => Monad m where
(>>=) :: m a -> (a -> m b) -> m b
(>>) :: m a -> m b -> m b
return :: a -> m a
ok so to find what Monad is you need to know what Applicative is
Applicative
Functor -> Applicative
class Functor f => Applicative f where
pure :: a -> f a
(<*>) :: f (a -> b) -> f a -> f b
Prelude> (,) <$> [1, 2] <*> [3, 4]
[(1,3),(1,4),(2,3),(2,4)]
ok so to find what Applicative is you need to know what Functor is
Functor
class Functor f where
fmap :: (a -> b) -> f a -> f b
And we have Functors in Elixr …
(for example for each element in the list transform list to some other list)
But I see someone better explained than me
https://shane.logsdon.io/writing/functors-applicatives-and-monads-in-elixir/
