Subsets

A subset of a set is a collection of some of the things in the set. Formally, $A$ is a subset of $B$ , written mathematically as $A \subset B$ , if every element in LaTeX: A is also an element in $B$ .

Example: If $A = {a, b, c, d, e, f}$ and $B = {a, c}$ , then $B \subset A$ . $◼$

Example: $A \subset A$ , that is, a set is a subset of itself. $◼$

The symbol $◼$ denotes the end of an example or explanation.

The empty set is the set with no elements. It is written as $\emptyset$ .

Example: The empty set is a subset of every set because it contains no elements, so every element in it is in any set. $◼$

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