# Triangular Commutative Diagram in Latex

I have made the following diagram. But I want the arrow to thick and long. How to do it?

\begin{tikzcd}[column sep=small]

X \supseteq \phi^{-1}(V) \arrow{r}{\varphi}  \arrow[swap]{rd}{f \circ \varphi}

& V \subseteq Y \arrow{d}{f} \\

& k
\end{tikzcd}


Making diagrams with the psmatrix environment is another possibility:

\documentclass{article}
\usepackage{amssymb}
\usepackage{pst-node}

\begin{document}

$\begin{psmatrix}%[column sep=large] X \supseteq \phi^{-1}(V) & V \subseteq Y \\ & k \psset{arrowinset=0.12,linejoin=1, arrows=->, labelsep=1pt} \ncline{1,1}{1,2}\naput{\varphi} \ncline{1,1}{2,2}\nbput[nrot=:U]{f \circ \varphi} \ncline[nodesep=2pt]{1,2}{2,2}\naput{f} \end{psmatrix}$

\end{document}


First off, you specified column sep=small which reduces the arrow length. With column sep=large, for example, they will be longer. Then you can specify the arrow tip style with a tikzcdset:

\documentclass[tikz,border=3.14mm]{standalone}
\usepackage{amsmath,amssymb,tikz-cd}
\usetikzlibrary{arrows.meta}

\tikzcdset{arrow style=tikz,diagrams={line width=2pt,>={Stealth[round,length=8pt,width=5pt,inset=2.75pt]}}}

\begin{document}
\begin{tikzcd}[column sep=large]
X \supseteq \phi^{-1}(V) \arrow{r}{\varphi}  \arrow[swap]{rd}{f \circ \varphi} & V \subseteq Y \arrow{d}{f} \\
& k
\end{tikzcd}
\end{document}


As for the line thickness, thanks to egreg, you can do it by adding an append style command.

\documentclass[tikz,border=3.14mm]{standalone}
\usepackage{amsmath,amssymb,tikz-cd}
\usetikzlibrary{arrows.meta}

\tikzcdset{
every arrow/.append style={line width=1pt},
arrow style=tikz,
diagrams={line width=2pt,>={Stealth[round,length=8pt,width=5pt,inset=2.75pt]}}}

\begin{document}
\begin{tikzcd}[column sep=large]
X \supseteq \phi^{-1}(V) \arrow{r}{\varphi}  \arrow[swap]{rd}{f \circ \varphi} & V \subseteq Y \arrow{d}{f} \\
& k
\end{tikzcd}
\end{document}


• Hi, you can see this my recent question....tex.stackexchange.com/questions/596366/… Jul 16 at 8:00
• @Sebastiano Yes, of course, I was referring to this question in my answer. But egreg found a way to increase the line width in his answer here. Jul 16 at 16:38

One more tikz-cd solution with using mathrlap in placement od top right node:

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

\begin{document}
$\begin{tikzcd}[sep=large, every arrow/.append style={-{Straight Barb[scale=0.8]},semithick} ] X \supseteq \phi^{-1}(V) \rar["\varphi"] \drar["f \circ \varphi"'] & V \mathrlap{\subseteq Y} \dar["f"] \\ & k \end{tikzcd}$
\end{document}


I'm not really sure you want thicker arrows. Anyway, here it is, with some changes to make the arrows pointing to the correct object.

\documentclass{article}
\usepackage{amsmath,tikz-cd}

\begin{document}

\begin{tikzcd}[every arrow/.append style={line width=0.6pt}]
\makebox[0pt][r]{$X \supseteq{}$} \phi^{-1}(V)
\arrow[r,"\varphi"]
\arrow[rd,"f \circ \varphi"'] &
V \makebox[0pt][l]{${}\subseteq Y$}
\arrow{d}{f} \\
& k
\end{tikzcd}

\end{document}


It might make sense to issue the change to line width the default: issue

\tikzcdset{
every arrow/.append style={line width=0.6pt},
}


in the document preamble.

For comparison, here's the output without changing the line width.