Re: confusing positional arguments- Functions are defined with partial application in mind. So, is it more likely you are mapping values over a list or lists over a value?

This is usually more readable as well. Consider:

  λ: 3 `elem` [1,2,3]

"Is 3 an element of 1,2,3?"

Also, div is not the same as (/):

  λ: 3 / 2
  1.5
  λ: 3 `div` 2
  1