```tex \documentclass[a4paper,11pt,twoside]{article} \usepackage{fancyhdr} \usepackage{verbatim} \usepackage{indentfirst} % primul paragraf din fiecare sectiune va fi indentat \usepackage[english]{babel} \usepackage{epsfig} %\usepackage{eucal} %\usepackage{mathptmx} \usepackage{longtable} \usepackage{caption} \usepackage{hanging} \usepackage{pifont} \usepackage{wrapfig} % The final heading of the journal will be slightly different. Do not modify these lines. \fancypagestyle{plain} {\small INTERNATIONAL} %\renewcommand{\headrulewidth}{0.1pt} \begin{document} \title{User} % Attention to capitalization of first letter in title \author{Shao} % Attention to the initials of first name \date{}%must be empty \maketitle {\small %Signature \begin{abstract} In order to {\bf Keywords:} tag recommendation \end{abstract} } \section{Introduction} As a new \section{The overall framework} will be conducted. \subsection{Layer 1 algorithm structure} In the first layer algorithm \begin{equation} L_i=\{(l_{i1}:f'_{l_{i1}}),(l_{i2}:f'_{l_{i2}}),...,(l_{ie}:f'_{l_{ie}})\}\label{equation:6} \end{equation} \end{document} ``` 这是出错的公式,请问大佬们如何解决