Subset/Examples/Abstract Example 3

Example of Subset
Let $A$ denote the set:
 * $A := \set {1, 2, 3}$

Let $B$ denote the set:
 * $B := \set {\&, 3, +, 1, 2}$

Then:
 * $A \subseteq B$
 * $A \subseteq A$
 * $B \subseteq B$