从 pdfLaTeX 转到 XeLaTeX

Question

我有这个很长的序言，我正在努力切换到 XeLaTeX。我正在使用 PdfLaTeX，但由于我想更改一些字体，我想切换到 XeLaTeX。我尝试加载 polyglossia 而不是 Babel，但它说 XeLaTex 没有成功。我发布了我的序言和我的日志。谢谢大家。NC

== 序言 == （不要看评论）

 \documentclass[12pt,a4paper,twoside,titlepage]{article}
 \usepackage{polyglossia}
 \setdefaultlanguage{italian}
\setotherlanguages{german}


\usepackage{newtxtext} 
\usepackage{textcomp}
\usepackage{xpatch,amsmath,systeme,mathtools}
\let\xleftrightarrow\undefined
\xpatchcmd{\@thm}{\fontseries\mddefault\upshape}{}{}{} % same font as thm-header
\xpatchcmd{\@def}{\fontseries\mddefault\upshape}{}{}{} % same font as thm-header

\makeatletter
\newcommand\xleftrightarrow[2][]{%
\ext@arrow 9999{\longleftrightarrowfill@}{#1}{#2}}
\newcommand\longleftrightarrowfill@{%
\arrowfill@\leftarrow\relbar\rightarrow}
\makeatother

\usepackage{amsfonts}

\DeclareMathOperator{\spn}{Span} %definisco operatore span con \spn per la parte generatrice di una fam. di vettori.
\DeclareMathOperator{\tr}{tr} % definisco operatore tr con \tr per la traccia di una matrice.
\DeclareMathOperator{\rg}{rang} %definisco operatore rang con \rg per il rango di una matrice.

\usepackage{amssymb}
\let\openbox\relax
\usepackage{amsthm, thmtools}
\usepackage{makeidx}
\usepackage{graphicx}
\usepackage{mdframed}
\usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry}
\usepackage{float}
\usepackage{ulsy}
\usepackage[T1]{fontenc}
\usepackage{wasysym}
\usepackage{tikz}
\usetikzlibrary{decorations.pathreplacing,calc,matrix}
\usepackage{pdfpages}
\usepackage{eso-pic}
\usepackage{hyperref}
    \hypersetup{
    colorlinks=false, %set true if you want colored links
    linktoc=all,     %set to all if you want both sections and subsections linked
}
\usepackage{sectsty}
\usepackage{fancyhdr}
\usepackage{nicematrix}
\usepackage{subfloat}
\usepackage{aligned-overset}


\sectionfont{\Huge}


\author{Niccolò Cavallini}
\title{Elementi di Algebra lineare}
\date{}

\textwidth16cm
\textheight23cm
\topmargin0mm
\headheight15mm
\headsep10mm
\oddsidemargin0mm
\evensidemargin0mm
\parindent0mm




% DIMOSTRAZIONE - STRUTTURA
%   fbox{
%       \parbox{0.97\textwidth}{
%                            \begin{center}
%                                        DIMOSTRAZIONE PER #1
%                             \end{center}  
%                        #2 \ \ \ \ $\blacksquare$
%  }
%}
%dove #1 è il METODO e #2 è il TESTO della dim.

\renewcommand{\emptyset} {\varnothing}
\newcommand {\vecl}{\overrightarrow}






\begin{document}

== 日志 == 请参见此处：Dropbox（超出字符数限制）