好的。我找到了这个Tikz 编辑器，但是当我复制并粘贴代码时，我无法让它呈现。这是我的设置（看起来很糟糕......）：
\documentclass[12pt]{amsart} \usepackage{amsfonts}
\usepackage{amsmath,graphicx,amssymb,amsthm} \usepackage{amsmath}
\usepackage{amssymb}
\usepackage{graphicx}
\setcounter{MaxMatrixCols}{30}
\usepackage{comment} \usepackage{tikz}
\providecommand{\U}[1]{\protect\rule{.1in}{.1in}} %EndMSIPreambleData
\addtolength{\textheight}{10mm} \addtolength{\textwidth}{25mm}
\addtolength{\oddsidemargin}{-15mm}
\addtolength{\evensidemargin}{-15mm} \addtolength{\topmargin}{-10mm}
\usepackage[a4paper, total={6in, 8in}]{geometry}
\newtheorem{set}{set}[section] \newtheorem{theorem}[set]{Theorem}
\theoremstyle{plain}
\newtheorem{acknowledgement}[set]{Acknowledgement}
\newtheorem{algorithm}[set]{Algorithm} \newtheorem{axiom}[set]{Axiom}
\newtheorem{case}[set]{Case} \newtheorem{claim}[set]{Claim}
\newtheorem{conclusion}[set]{Conclusion}
\newtheorem{condition}[set]{Condition}
\newtheorem{conjecture}[set]{Conjecture}
\newtheorem{corollary}[set]{Corollary}
\newtheorem{criterion}[set]{Criterion}
\newtheorem{definition}[set]{Definition}
\newtheorem{example}[set]{Example}
\newtheorem{exercise}[set]{Exercise} \newtheorem{lemma}[set]{Lemma}
\newtheorem*{lemma*}{Lemma} \newtheorem{notation}[set]{Notation}
\newtheorem{problem}[set]{Problem} \newtheorem*{problem*}{Problem}
\newtheorem{proposition}[set]{Proposition}
\newtheorem{remark}[set]{Remark} \newtheorem{solution}[set]{Solution}
\newtheorem{summary}[set]{Summary} \newcommand{\h}{\mathcal{H}}
\newcommand{\abs}[1]{\left\vert#1\right\vert}
\newcommand{\norm}[1]{\left\Vert#1\right\Vert}
\newcommand{\rad}{\text{rad }} \allowdisplaybreaks[4]
\title{}
\author{} \date{}
\begin{document}
\maketitle
\begin{problem*} Show that a commutative diagram
%
https://tikzcd.yichuanshen.de/#N4Igdg9gJgpgziAXAbVABwnAlgFyxMJZABgBpiBdUkANwEMAbAVxiRBAF9T1Nd9CUARnJVajFm07cQGbHgJEATCOr1mrRCADCAfWBgA1II5Sec-ktKLRaiZoCiew8dMze8gSSs3xG9lzM+BSFvVV9JALdzYOQAZlJBH3U2AEEnE0jZIM8AFhUxZM0AIR1CTPcLFDzrMMKQABFS1yyPIgBWfNs-XTLpFsrkDpqCuxBHXsDWlAA2BKTRtP0AWhdy6M8Adk7w4qcVjL6KmK3hrrZG5dXD9aIADlCRv2ajz3vKWtHnm5QATm26r7ZIh-U47fyiGBQADm8CIoAAZgAnCAAWyQZBAOAgSGEIAYWDAfigEBwOEhIGoAAsYHQoGxIITXEjUTjqFikMpHmwADrcxhoSl0JxGA4I5FoxCc9mIeJ4ugAIxgDAACi82AwYPCcBSuZp4cKrmKWYg8pjsYgOniCUSSWS6VSaXTNAzWJFmRLLdLZWdNLzFTghfoRTqGAqlarviBEVgoZTtW7xUhZdLZnLFSq1Zpo7HtR8-JSmgnjVLzamfSAoU1qKH0xGgZoNVqmYnEKnpVtdSAANaF6TupBt833NPhzNRmNxnXlgBWvaNEo70r+nd5-MFVZHGcjjfjfZbw+lggx5b9MAD6RDYa39fHOebxsXQ7zPO5ULoKJRQomIH7iGXh+PMF9W-X9-3NQRcXLStLlFH8WyPNlwMgsECxg+8JQgxCcU5csezQosMNxQ9vTBWc0OrK86ymW9JwInFk3A00a1HSNs0nZ9fW5f1AzAfZ0OwrDEEES0Tz5BgBR4vi6KEz1wNTfFGU0YlSXJB1aXpAhXT3Y1BFNQ8OwUm0VPtEBqXU51NJ1AMsAYDTGQo2sxx3fihJLeiHJYm9nI4kBeTfD9JNWCgOCAA
\begin{tikzcd} {} \arrow[r, no head, dotted] & {} \arrow[r,
"\alpha_{n+1}"] & C_{n+1} \arrow[dd, "f_{n+1}"] \arrow[rd, "g_n"] &
& B_n \arrow[r, "\alpha_n"] \arrow[dd, "\gamma_n"] & C_n \arrow[dd,
"f_n"] \arrow[rd, "g_{n-1}"] &
& B_{n-1} \arrow[r, "\alpha_{n-1}"] \arrow[dd, "\gamma_{n-1}"] & {}
\arrow[r, no head, dotted] & {} \\
& & & A_{n} \arrow[ru, "k_n"] \arrow[rd, "j_n"'] &
& & A_{n-1} \arrow[ru,
"k_{n-1}"] \arrow[rd, "j_{n-1}"'] &
& & \\ {} \arrow[r, no head, dotted]
& {} \arrow[r, "\beta_{n+1}"'] & E_{n+1} \arrow[ru, "h_n"']
& & D_n \arrow[r,
"\beta_{n}"'] & E_n \arrow[ru, "h_{n-1}"]
& & D_{n-1}
\arrow[r, "\beta_{n-1}"'] & {} \arrow[r, no
head, dotted] & {} \end{tikzcd}
with the two sequences across the top and bottom exact, gives rise to
an exact sequence where the maps are obtained from those in the
previous diagram in the obvious way, except that $B_n \to C_n \oplus
D_n$ has a minus sign in one coordinate. \end{problem*}
\end{document}
我究竟做错了什么？这里这是我尝试使用编辑器做的事情。
答案1
该网站不是通用的 TikZ 编辑器，而是专门tikz-cd用于制作交换图的编辑器。它生成的代码使用了tikz-cd包，而你的序言中没有这个包。因此，你需要做的就是添加
\usepackage{tikz-cd}
在序言中