我正在使用此处提供的 Elsevier 模板撰写论文https://www.ctan.org/pkg/els-cas-templates/。我不知道如何添加数学科目分类。我目前正在写的工作看起来像这样
\documentclass[a4paper,fleqn]{cas-sc}
\usepackage[numbers]{natbib}
\usepackage{amsthm,amssymb,tikz-cd}
\usetikzlibrary{shapes.geometric}
\theoremstyle{definition}
\newtheorem{definition}{Definition}[section]
\newtheorem{example}{Example}[section]
\theoremstyle{plain}
\newtheorem{theorem}{Theorem}[section]
\newtheorem{lemma}{Lemma}[section]
\newtheorem{proposition}{Proposition}[section]
\newtheorem{corollary}{Corollary}[section]
\makeatother
%%%Author macros
\def\tsc#1{\csdef{#1}{\textsc{\lowercase{#1}}\xspace}}
\tsc{WGM}
\tsc{QE}
\tsc{EP}
\tsc{PMS}
\tsc{BEC}
\tsc{DE}
%%%
\begin{document}
\let\WriteBookmarks\relax
\def\floatpagepagefraction{1}
\def\textpagefraction{.001}
\shorttitle{Ordering of matrices by precede operator}
\shortauthors{Amirul Aizad Ahmad Fuad and Tahir Ahmad}
\title [mode = title]{Ordering of matrices by precede operator}
\author[1]{Amirul Aizad Ahmad Fuad}[type=editor,
orcid=0000-0003-0819-4922]
\cormark[1]
\fnmark[1]
\ead{[email protected]}
\address[1]{Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru, Malaysia}
\author[2]{Tahir Ahmad}
\cormark[2]
\fnmark[2]
\ead{[email protected]}
\address[2]{Centre for Sustainable Nanomaterials, Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, 81310 Johor Bahru, Malaysia}
\cortext[cor1]{Corresponding author}
\cortext[cor2]{Principal corresponding author}
\begin{abstract}
We investigated partial orders on a set of real square matrices and introduced a new order relation based on several function compositions. We also established some results as the consequences of the new partial order on square matrices and symmetric matrices.
\end{abstract}
\begin{keywords}
Matrix partial order \sep Precede partial order \sep Symmetric matrices
\end{keywords}
\maketitle
\section{Introduction and Motivation}
\label{sec:intro}
\end{document}
生成结果：
我想要像这样添加 MSC（突出显示）：
答案1
尝试
\begin{keywords}
\MSC 15A09 \sep 15A57 \sep 15A24
Matrix partial order \sep Precede partial order \sep Symmetric matrices
\end{keywords}
请参阅下面的文档（摘自链接中的“cas-sc-template.tex”文件假如)：
\begin{keyword}
%% keywords here, in the form: keyword \sep keyword
%% PACS codes here, in the form: \PACS code \sep code
%% MSC codes here, in the form: \MSC code \sep code
%% or \MSC[2008] code \sep code (2000 is the default)
\end{keyword}