Let $P = (\Omega, \mathcal{F}, \mathbb{P})$ be a D1159: Probability space such that
Let $B \subseteq \mathbb{R}$ be a D5113: Standard real Borel set.
(i) | $X : \Omega \to \mathbb{R}$ is a D3161: Random real number on $P$ |
Then
\begin{equation}
\{ X \in - B \}
= \{ - X \in B \}
\end{equation}