Stage 19 · Sets & Intervals — the Language of Functions

19.1.2 Elements and Definiteness

19.1 From "a Kind of Thing" to a Set

Point 2 of 4

Core idea

Each thing is either inside the circle or outside it, never "maybe"; every member inside is called an element, written a.

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 · 19.1.2 Elements and Definiteness