Stage 19 · Sets & Intervals — the Language of Functions

19.1.3 Distinctness and Order-Free

19.1 From "a Kind of Thing" to a Set

Point 3 of 4

19.1.3 Distinctness and Order-Free

Core idea

A roll call lists no one twice and doesn't care who comes first, so {1,2,2} is just {2,1}.

Module goal. Build the intuition behind a set — bundling "objects that meet the same standard" into a single whole, and learning to write it down
eastmath.com · 19.1 From "a Kind of Thing" to a Set · 19.1.3 Distinctness and Order-Free