# Arrow tail style using tikz-cd

For my tikz-cd diagrams, I am trying to define an arrow with a cross at the tail. I feel like this should be easy, but have not found an easy way of doing this yet.

• A cross like in + or x? – egreg Jun 12 '19 at 10:54

You can use Rays arrow tips from the arrows.meta TikZ library:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{cd, arrows.meta}

% '+' arrow tip
%
% You may declare the '+' arrow tip centrally here if you wish, or in a
% particular 'tikzpicture' environment as shown below.
% Thanks to Håkon Marthinsen for this arrow tip specifiation
% (<https://tex.stackexchange.com/a/340406/73317>).
%
%\tikzset{+ /.tip = {Bar[sep=1.5pt 2,width=3pt 4]_[sep=0]}}

\begin{document}
\begin{tikzcd}
A \arrow[rd] \arrow[r, {Rays[]}->, "\phi"] & B \\
& C
\end{tikzcd}

\begin{tikzcd}
A \arrow[rd] \arrow[r, {Rays[n=8]}->, "\phi"] & B \\
& C
\end{tikzcd}

% '+' arrow tip from <https://tex.stackexchange.com/a/340406/73317>
\begin{tikzcd}[+ /.tip = {Bar[sep=1.5pt 2,width=3pt 4]_[sep=0]}]
A \arrow[rd] \arrow[r, +->, "\phi"] & B \\
& C
\end{tikzcd}

\end{document}


• What about an “upright cross”? – egreg Jun 12 '19 at 10:53
• Dear @egreg, please consult the latest version of my answer. It features what I would call a '+' arrow tip—I don't mind if you want to call it an “upright cross”. :-) – frougon Jun 12 '19 at 11:50
• Exactly what I meant, thanks! – egreg Jun 12 '19 at 12:21
• @egreg I shall take a screenshot of your comment and keep it locked in a safe like a check from Don Knuth. ;-) – frougon Jun 12 '19 at 12:23