# Upside down reversion for a Greek letter

Like this?

```
\documentclass{article}
\usepackage{graphics}
\begin{document}
\[ \Omega\quad\raisebox{\depth}{\scalebox{1}[-1]{$ \Omega $}} \]
\end{document}
```

*Added*:

Simpler, the `amssymb`

package defines the `\mho`

command for the conductance unit:

The best way to achieve this is with `\rotatebox[origin=c]{180}(\someSymbol)`

, from `graphicx`

. It doesn’t rely on any undocumented feature, and it doesn’t need any adjustment with `\raisebox`

, although you might still prefer to add one.

There are two different ways to read your question: a 180° rotation and a vertical reflection are two different meanings of “upside down” that are not the same, unless your glyph has bilateral symmetry. Since a vertical reflection is the horizontal reflection of a 180° rotation, you can get the latter with `\reflectbox{\rotatebox[origin=c]{180}{\someSymbol}}`

.

```
\documentclass{article}
\usepackage[T1]{fontenc} % Or your font packages of choice.
\usepackage{textcomp}
% To fit this MWE inside the size limits of an image on TeX.SX:
\usepackage[paperwidth=10cm]{geometry}
\usepackage{graphicx}
\begin{document}
The four symmetries of a rectangle form a group \(\mathbf{V}\) of order 4
isomorphic to a dihedral group, a Klein group, or the Cartesian product
\( \left( \mathbf{Z}_2 \times \mathbf{Z}_2 \right) \). It is the smallest
non-cyclic group.
We can illustrate it geometrically as the four transformations possible by
reflecting a glyph in a rectangular box, let’s say \(\zeta\), across the
horizontal axis to get \reflectbox{\(\zeta\)}, the vertical axis to get
\raisebox{\depth}{\scalebox{1}[-1]{\(\zeta\)}}, neither to get the original \(\zeta\), or both
to get \raisebox{\depth}{\scalebox{-1}[-1]{\(\zeta\)}}. The latter is the same as rotating
the rectangle by {180\textdegree} to get \rotatebox[origin=c]{180}{\(\zeta\)}.
Any composition of these operations is another operation. For example,
rotating {180\textdegree} and reflecting over the horizontal axis gets
\reflectbox{\rotatebox[origin=c]{180}{\(\zeta\)}}, the same as a reflection
across the vertical axis.
\end{document}
```

In a real paper, you’d want to declare the symbol with `\newcommand`

rather than insert this code into the running text. If it’s not an “ordinary” math symbol, you might additionally want to wrap it in a command that changes its math class, such as `\mathop`

.

### PS

You ask which other letters can be “rotated by amssymb,” like `\Omega`

and `\mho`

. There are a number of such “turned” letters in the letterlike symbols block of Unicode, as well as other mathematical symbols that resemble rotated Greek letters, such as ∇, ∐, ∀ and ∃. (In traditional LaTeX, there are no commands `\Alpha`

or `\Epsilon`

, and the Latin A and E stand in for them.) Barbara Beeton brings up that V looks like an inverted Λ. You can use any of them with `unicode-math`

, either directly, by codepoint, or with a symbolic name that is usually backward-compatible. Since you tagged this question for PDFTeX, in that engine, look them up in “The Comprehensive LaTeX Symbol List.”