📝 Set Representation

A Set is a well-defined collection of distinct objects. Let's look at a basket of fruits. We can represent this set in different ways.

Our Fruit Set F

Lists all elements clearly separated by commas inside curly braces.

F = { 🍎, 🍌, 🍇, 🍊, 🍓 }

U Universal Set

The Universal Set (U or ε) contains all possible elements under consideration. Every other set we discuss is a subset of the Universal Set.

U
C (Citrus)
Y (Yellow)
🍊
🍋
🍌
🍎
🍇
🍓
🍉

Universal Set (U)

The entire grocery store inventory of fruits.

{ 🍎, 🍊, 🍋, 🍌, 🍇, 🍓, 🍉 }

Set C (Citrus)

{ 🍊, 🍋 }

Set Y (Yellow Fruits)

{ 🍌, 🍋 }

The Empty Set

A set that contains no elements is called the empty set or null set. It is denoted by or {}. Try filtering the basket below.

Find fruits that are:
🍎 🍌 🍇 🍊 🍓
A = { 🍎, 🍌, 🍇, 🍊, 🍓 }

All fruits in our basket.

Finite vs Infinite Sets

A Finite Set has a specific, countable number of elements. An Infinite Set continues endlessly.

Finite Set

Countable

Set A = { Fruits currently in my bowl }.
We can easily count them. There are exactly 4.

🍎 🍌 🍊 🍇
Cardinality: |A| = 4

Infinite Set

Unending

Set N = { Natural Numbers }.
Imagine picking a fruit, tagging it with a number, forever.

Cardinality: |N| = ∞

Subsets

Set A is a subset of Set B (A ⊆ B) if every element in A is also in B. Build Set A by clicking fruits below!

Target Set B (The Standard Basket)

🍎 🍌 🍇 🍊

Click to add to your Set A:

Your Set A is empty {}
🤔
A ⊆ B ?

Add some fruits to check if it's a subset!

P(S) Power Set

The Power Set P(S) is the set of all possible subsets of S, including the empty set and S itself. If S has n elements, P(S) has 2n elements.

Build Set S (Max 3 items)

Current Set S
S = { }

Results: P(S)

Size: 2⁰ = 1 subsets
∅ (Empty Set)

Set Operations

Let's look at operations like Union, Intersection, and Complement. We will use a practical example of 10 Animals at a rescue center as our Universal Set U.

Choose Operation:

Select an operation

Click a button above to see the result and visual representation.

U
Set A
Climbers
Set B
Long Tails
🐻
🐼
🐨
🐱
🐭
🐶
🦊
🐯
🐹
🐰