Monads don’t receive nor send anything.

Arrays are a type that admits a monad instance, what do they send and receive?

If that were Haskell instead of python, it would still work, because tmp is never mutated. So it's not really state in that sense, it's just a binding.

    x input = show tmp
      where tmp = input * 5

It would be a different story if you had something like

    class IntState:
      def __init__(self, val):
        self.val = val
      
      def x(input):
        self.val += input
        return str(val)