Day 2 · Types of Sets and Subsets

An empty set has no members at all. It is written as ∅ or { }.

A finite set has a countable number of members. An infinite set has unlimited members, like the set of natural numbers.

Set A is a subset of set B if every member of A is also in B. We write this as A ⊆ B.

Activity: If A = {1,2} and B = {1,2,3,4}, check whether A is a subset of B.