Let $F=(f;A;B)$ is a morphism of the category $\mathbf{Rel}$ (the category whose objects are sets and morphisms are defined as binary relations).
How to name and how to denote $f$ when we know $F$?
I propose to call $f$ the graph of $F$. Right name?
But how to denote it? Are there a standard notation?
I propose the following (non-standard) notation: $\mathrm{GR}\, F= f$.