# Talk:Preimage of Singleton

Let $\mathcal R^{-1}\left({ \left\{ t \right\} }\right)$ denote the image of $\left\{ t \right\}$ under $\mathcal R$."
Let $\mathcal R^{-1}\left({ \left\{ t \right\} }\right)$ denote the image of $\left\{ t \right\}$ under $\mathcal R^{-1}$."