# Blank or no arrow in a commutative diagram

I learned from this nice post that a commutative diagram with the CD environment can have arrows pointing and their commands:

• right

@>>>

• left

@<<<

• down

@VVV

• up

@AAA


Question: what is the case that if I just like to keep a blank spacing without arrow? What is the command?

• A MWE please! – Svend Tveskæg May 27 '14 at 17:23
• excuse me, this is just asking a command or function... – wonderich May 27 '14 at 17:24
• May I suggest that you use the packages xypic or tikz-cd for drawing commutative diagrams? They have somewhat intuitive syntax... But, I will post an answer too... :-) – kan May 27 '14 at 17:33
• Thanks kan, a similar but not the same issue , but with MWE. See the new post – wonderich May 27 '14 at 17:39
• You don't have to excuse yourself. Just post some compilable code next time; that's all. – Svend Tveskæg May 27 '14 at 18:07

The example is taken verbatim from Milne's notes on amscd package:

Here is the MWE showing all the possible arrows in the amscd package:

\documentclass{amsart}
\usepackage{amscd}
\begin{document}
$\begin{CD} A @<<< B @>>> C\\ @. @| @AAA\\ @. D @= E \end{CD}$
\end{document}


The output:

In particular, the complete list of arrows is:

• right

@>>>

• left

@<<<

• down

@VVV

• up

@AAA

• horizontal equals to

@=

• vertical equals to

@|

• empty arrow

@.


PS: You'd probably appreciate my comment under your question post if that is coming from someone with more experience, so please see Milne's Guide to Commutative Diagram Packages for some words about his personal experience.

• I see, Kan, thanks, it is pretty clear! +1. – wonderich May 27 '14 at 18:23