Set Theory - Functions & Set Duplicates

Question

Hey there! I'm really looking to understand a property of set theory. I've built a function PS() that takes in a set and returns a set. However, the output set may have duplicates. The definition of a set says that a set may not have duplicates (ignoring other more lax forms of set theory). To be correct, does my function need to REMOVE duplicates from its output set to be correct, or do the laws of set theory mean that a set like {A, A, B, C} "reduces" to {A, B, C} automatically?

Answer 1

So Alex F.,

Your first choice. Make your function output a valid set. Do you have ideas on how you might do this efficiently (such as, ordering the set in processing then sorting to remove duplicate members)?

-- Cheers, -- Mr. d.