# Ceiling Function/Examples/Ceiling of Minus One Half

## Theorem

$\ceiling {- \dfrac 1 2} = 0$

where $\ceiling x$ denotes the ceiling of $x$.

## Proof

We have:

$0 \ge - \dfrac 1 2$

and:

$-1 = - \dfrac 2 2 < - \dfrac 1 2$

Hence $0$ is the ceiling of $- \dfrac 1 2$ by definition.

$\blacksquare$