# How do I produce this Greek letter koppa: Ϟ in pdfLaTeX?

I have been trying to typeset the character GREEK LETTER KOPPA. It has not been working. I know the Unicode number (U+03DE), and tried the command ^^3de and ^^3DE. Neither worked. I also tried \char and \char", but those didn't work either, other symbols get produced.

Does anybody have an idea as to how I can get my computer to typeset the symbol Ϟ?

MWE:

\documentclass[a4paper, 12pt]{article}
\usepackage[ngerman, polutonikogreek]{babel}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{arevmath}
\usepackage{lmodern}
\fontfamily{lmr}\selectfont
\usepackage{geometry}
\geometry{
a4paper,
top=30mm,
left=25mm,
right=20mm,
bottom=20mm,
}

\begin{document}
\selectlanguage{ngerman}

$\Koppa$

\end{document}

• Do you use either LuaLaTeX or XeLaTeX? – Mico Apr 25 at 19:58

Using arevmath package you have the request symbol.

\documentclass{article}
\usepackage{arevmath}
\begin{document}

$\Koppa$

\end{document}

• I have tried, and I get the following error message: ! LaTeX Error: Command \qoppa' already defined. See the LaTeX manual or LaTeX Companion for explanation. Type H <return> for immediate help. ... l.28 ...Symbol{\qoppa}{\mathord}{extraitalic}{162} % uni03D9 ? – rensemil Apr 25 at 19:43
• @rensemil - It looks like you're loading some font-related packages in addition to arevmath. Have you tried not loading arevmath and typing \Koppa (in math mode, presumably)? – Mico Apr 25 at 19:56
• I know. That error message even occurs if I don't type \Koppa in the document. As soon as I add the arevmath package, the error message pops up. – rensemil Apr 25 at 19:57
• @Mico Thank you very much for your technical support. – Sebastiano Apr 25 at 20:00
• @rensemil In my TeX Live installation, a command \qoppa is defined by the packages teubner, alphabeta, and boisik, and the Babel language definitions greek, ibygreek, and bgreek, as well as by arevmath. Are you loading any of those? – zwol Apr 25 at 20:12

You have it in the cm-unicode fonts, to be used with xelatex. They also have the archaic koppa. If you can type it directly on your keyboard, XeLaTeX will understand it. Other than that I defined two commands to obtain them (note the hexadecimal code is not the official unicode hexadecimal number):

\documentclass[12pt]{article}
\usepackage{fontspec}
\setmainfont{CMU Serif}
\def\koppa{\char "03DF}
\def\archaickoppa{\char "03D9}

\begin{document}

\end{document}


• @Bernard Hi, have you seen my message for \vast command? – Sebastiano Apr 25 at 20:11
• @rensemil: I think this message is for me. It's unrelated to your question.@Sebastiano>. I've found it this morning (grazie tante!), but didn't have time to look at your link. I've taken alook this evening. It seems to be a command to obtain delimiters still larger than \Bigg. I dihad never heard of this construct, but I'm no guru. – Bernard Apr 25 at 20:12
• My compliments for your answer that I have upvoted. – Sebastiano Apr 26 at 21:48
• Thanks for your kind appreciation, @Sebastiano! – Bernard Apr 26 at 22:06

If you have a font on your system that you know has that character you can use a package such as fontspec or mathspec to typeset your document (either whole or part, as you prefer) in that font.

• Unfortunately, I don't know either of those things. – rensemil Apr 25 at 19:46
• Fair enough. For what it's worth, some Google fonts that support that character are Noto Serif, Cardo and Tinos (all serif; some sans serif ones are Noto Sans, Fira Sans and Arimo). – Miztli Apr 25 at 19:52
• @Miztli Don't worry I voted the same you for the effort and the correct answer. – Sebastiano Apr 25 at 19:59
• Could you edit your answer to include a MWE (minimal working example)? – Miztli Apr 25 at 20:04
• Create a separate very simple (stripped down to the bare bones, including only the packages and content relevant for this issue) version of the code you have, click "edit" below your question and then include it in a code block (use the button with two curly braces). – Miztli Apr 25 at 20:11

Here is one definition that works with the modern toolchain. It requires LuaLaTeX or XeLaTeX and an OpenType or TrueType font containing the glyph.

\documentclass[varwidth]{standalone}
\usepackage{mathtools}
\usepackage{unicode-math}

\defaultfontfeatures{Scale = MatchLowercase }
\setmainfont{DejaVu Serif}[Scale = 1.0]
\setmathfont{TeX Gyre DejaVu Math}

\newcommand\koppa{\ifmmode%
{\mathord{\text{^^^^03de}}}\else%
^^^^03de\fi}

\begin{document}
Here is the symbol \koppa.

$$\koppa = \koppa_{\koppa_\koppa}$$
\end{document}


There are other ways to declare the symbol as well, including loading a font containing Ϟ as a symbol alphabet and using \DeclareMathSymbol, or loading the symbol in text mode from a \newfontfamily declared with fontspec, or defining it with \newunicodechar, or loading all Greek letters from that Unicode block with ucharclasses, or finding an OpenType math font that has the glyph, or plain TeX \char"03DE, or \symbol{"03DE}.

• Surely also your answer is very good. I have appreciated also this answer. – Sebastiano Apr 26 at 21:49

The problem was the inclusion of the polutonikogreek` package. Without it, everything works just fine.