Math & Science ⇒ Symbol

[Lumy]

Hello,

please help me. How can I write these two relations?


Thank you very much.

[frabjous]

Here are two ways of doing them. Pick the syntax you like better. (I can't tell any difference in output.) I'm sure there are other ways of doing it too.

Code: Select all

\documentclass{article}
% Setting the font to Times to match your sample (not important)
\usepackage[T1]{fontenc}
\usepackage{mathptmx}
% These packages are important
\usepackage{amsmath,amssymb}
\begin{document}
    \[
        f \mathrel{\mathop{\nrightarrow}_{R}^{u}} f \text{\quad and \quad} f \mathrel{\mathop{=}_{R}^{u}} f
    \]
    \[
        f \overset{u}{\underset{R}{\nrightarrow}} f \text{\quad and \quad} f \overset{u}{\underset{R}{=}} f
    \]
\end{document}

The resulting arrow isn't quite as long as yours. If that's important, I'm sure it can be changed.

overunder.png (3.76 KiB) Viewed 1942 times

[Lumy]

Perfect. Thank you very much.