Bounded Above Subset of Real Numbers/Examples/Closed Interval from Minus Infinity to 2

Example of Bounded Above Subset of Real Numbers
The subset $I$ of the real numbers $\R$ defined as:
 * $I = \hointl \gets 2$

is bounded above by, for example, $2$, $3$ and $4$, of which the supremum is $2$.

$2$ is also the greatest element of $I$.

The set of all upper bounds of $I$ is:
 * $\closedint 2 \to$