diff --git a/analyse-I.tex b/analyse-I.tex
index afe894d..6f9eaf4 100644
--- a/analyse-I.tex
+++ b/analyse-I.tex
@@ -1,38 +1,9 @@
 \documentclass[a4paper,10pt]{article}
 %\documentclass[a4paper,10pt]{scrartcl}
 
-\usepackage{xltxtra}
-\usepackage{pbox}
-\usepackage{mathtools}
-\usepackage{amssymb}
-\usepackage{tabularx}
-\usepackage[top=13pt, bottom=12pt, left=13pt, right=12pt]{geometry}
-% \setromanfont[Mapping=tex-text]{Linux Libertine O}
-% \setsansfont[Mapping=tex-text]{DejaVu Sans}
-% \setmonofont[Mapping=tex-text]{DejaVu Sans Mono}
-
-\title{}
-\author{}
-\date{}
-
-\let\oldcdot\cdot
-\let\oldbullet\bullet
-\let\oldvec\vec
-\let\olddot\dot
-\let\oldddot\ddot
-
-% \renewcommand{\cdot}{ }
-\renewcommand{\bullet}{\circ}
-% \renewcommand{\vec}{\mathbf}
-% \renewcommand{\dot}[1]{\frac{\mathrm{d}#1}{\mathrm{d}t}}
-% \renewcommand{\ddot}[1]{\frac{\mathrm{d^2}#1}{\mathrm{d}t^2}}
-\newcommand{\ccdot}{ }
-
-\setlength{\parindent}{0pt}
-\setlength{\parskip}{0pt}
+\input{common.tex}
 
 \begin{document}
-% \maketitle
 
 \begin{tabularx}{\textwidth}{ |X|X| }
 \hline
diff --git a/chimie.tex b/chimie.tex
index d8b8ad0..3df3854 100644
--- a/chimie.tex
+++ b/chimie.tex
@@ -1,26 +1,9 @@
 \documentclass[a4paper,10pt]{article}
 %\documentclass[a4paper,10pt]{scrartcl}
 
-\usepackage{xltxtra}
-\usepackage{pbox}
-\usepackage{mathtools}
-\usepackage{amssymb}
-\usepackage{tabularx}
-\usepackage{siunitx}
-\usepackage[top=13pt, bottom=12pt, left=13pt, right=12pt]{geometry}
-% \setromanfont[Mapping=tex-text]{Linux Libertine O}
-% \setsansfont[Mapping=tex-text]{DejaVu Sans}
-% \setmonofont[Mapping=tex-text]{DejaVu Sans Mono}
-
-\title{}
-\author{}
-\date{}
-
-\setlength{\parindent}{0pt}
-\setlength{\parskip}{0pt}
+\input{common.tex}
 
 \begin{document}
-% \maketitle
 
 \begin{tabularx}{\textwidth}{ |X|X| }
 \hline
diff --git a/common.tex b/common.tex
new file mode 100644
index 0000000..66d4edf
--- /dev/null
+++ b/common.tex
@@ -0,0 +1,36 @@
+\usepackage{xltxtra}
+\usepackage{pbox}
+\usepackage{mathtools}
+\usepackage{amssymb}
+\usepackage{tabularx}
+\usepackage{siunitx}
+\usepackage{unicode-math}
+\usepackage[top=13pt, bottom=12pt, left=13pt, right=12pt]{geometry}
+% \setromanfont[Mapping=tex-text]{Linux Libertine O}
+% \setsansfont[Mapping=tex-text]{DejaVu Sans}
+% \setmonofont[Mapping=tex-text]{DejaVu Sans Mono}
+
+\title{}
+\author{}
+\date{}
+
+\let\oldcdot\cdot
+\let\oldbullet\bullet
+\let\oldvec\vec
+\let\olddot\dot
+\let\oldddot\ddot
+
+% \renewcommand{\cdot}{ }
+\renewcommand{\bullet}{\circ}
+% \renewcommand{\vec}{\mathbf}
+% \renewcommand{\dot}[1]{\frac{\mathrm{d}#1}{\mathrm{d}t}}
+% \renewcommand{\ddot}[1]{\frac{\mathrm{d^2}#1}{\mathrm{d}t^2}}
+% \renewcommand{\frac}[2]{#1 / #2}
+\newcommand{\cdotbis}{ }
+
+\newcommand{\dif}{\mathrm{d}}
+
+\setlength{\parindent}{0pt}
+\setlength{\parskip}{0pt}
+
+% \everymath{\displaystyle}
\ No newline at end of file
diff --git a/physique-I.tex b/physique-I.tex
index 4ebb7e1..c4425db 100644
--- a/physique-I.tex
+++ b/physique-I.tex
@@ -1,39 +1,9 @@
 \documentclass[a4paper,10pt]{article}
 %\documentclass[a4paper,10pt]{scrartcl}
 
-\usepackage{xltxtra}
-\usepackage{pbox}
-\usepackage{mathtools}
-\usepackage{amssymb}
-\usepackage{tabularx}
-\usepackage[top=13pt, bottom=12pt, left=13pt, right=12pt]{geometry}
-% \setromanfont[Mapping=tex-text]{Linux Libertine O}
-% \setsansfont[Mapping=tex-text]{DejaVu Sans}
-% \setmonofont[Mapping=tex-text]{DejaVu Sans Mono}
-
-\title{}
-\author{}
-\date{}
-
-\let\oldcdot\cdot
-\let\oldbullet\bullet
-\let\oldvec\vec
-\let\olddot\dot
-\let\oldddot\ddot
-
-% \renewcommand{\cdot}{ }
-\renewcommand{\bullet}{\circ}
-% \renewcommand{\vec}{\mathbf}
-% \renewcommand{\dot}[1]{\frac{\mathrm{d}#1}{\mathrm{d}t}}
-% \renewcommand{\ddot}[1]{\frac{\mathrm{d^2}#1}{\mathrm{d}t^2}}
-% \renewcommand{\frac}[2]{#1 / #2}
-\newcommand{\cdotbis}{ }
-
-\setlength{\parindent}{0pt}
-\setlength{\parskip}{0pt}
+\input{common.tex}
 
 \begin{document}
-% \maketitle
 
 \begin{tabularx}{\textwidth}{ |X|X|X| }
 \hline
@@ -169,10 +139,10 @@
   $ \vec{r} = r \cdotbis \vec{e_r}$ \newline
   $ \vec{v} = \dot{r} \cdotbis \vec{e_r} + r \cdotbis \dot{\theta} \cdotbis \vec{e}_{\theta} + r \cdotbis \dot{\varphi} \cdotbis \sin(\theta) \cdotbis \vec{e}_{\varphi} $ \newline
   $ \vec{a} = \begin{pmatrix}
-		\ddot{r} - \dot{r} \cdotbis \dot{\theta}^2 - r \cdotbis \dot{\varphi}^2 \cdotbis \sin^2(\theta) \\
-		2 \cdotbis \dot{r} \cdotbis \dot{\theta} + r \cdotbis \ddot{\theta} - r \cdotbis \dot{\varphi}^2 \cdotbis \sin(\theta) \cdotbis \cos(\theta) \\
-		2 \cdotbis \dot{r} \cdotbis \dot{\varphi} \cdotbis \sin(\theta) + r \cdotbis \ddot{\varphi} \cdotbis \sin(\theta) + 2 \cdotbis r \cdotbis \dot{\varphi} \cdotbis \dot{\theta} \cdotbis \cos(\theta) \\
-	      \end{pmatrix} $ \newline
+                \ddot{r} - \dot{r} \cdotbis \dot{\theta}^2 - r \cdotbis \dot{\varphi}^2 \cdotbis \sin^2(\theta) \\
+                2 \cdotbis \dot{r} \cdotbis \dot{\theta} + r \cdotbis \ddot{\theta} - r \cdotbis \dot{\varphi}^2 \cdotbis \sin(\theta) \cdotbis \cos(\theta) \\
+                2 \cdotbis \dot{r} \cdotbis \dot{\varphi} \cdotbis \sin(\theta) + r \cdotbis \ddot{\varphi} \cdotbis \sin(\theta) + 2 \cdotbis r \cdotbis \dot{\varphi} \cdotbis \dot{\theta} \cdotbis \cos(\theta) \\
+              \end{pmatrix} $ \newline
   $ \frac{\mathrm{d}}{\mathrm{d}t} \cdotbis \vec{e_r} = \dot{\theta} \cdotbis \vec{e}_{\theta} + \dot{\varphi} \cdotbis \sin(\theta) \cdotbis \vec{e}_{\varphi} $ \newline
   $ \frac{\mathrm{d}}{\mathrm{d}t} \cdotbis \vec{e}_{\theta} = -\dot{\theta} \cdotbis \vec{e_r} + \dot{\varphi} \cdotbis \cos(\theta) \cdotbis \vec{e}_{\varphi} $ \newline
   $ \frac{\mathrm{d}}{\mathrm{d}t} \cdotbis \vec{e}_{\varphi} = -\dot{\varphi} \cdotbis \sin(\theta) \cdotbis \vec{e_r} - \dot{\varphi} \cdotbis \cos(\theta) \cdotbis \vec{e}_{\theta} $ \newline
diff --git a/physique-II.tex b/physique-II.tex
index ebef799..964ef1a 100644
--- a/physique-II.tex
+++ b/physique-II.tex
@@ -1,40 +1,9 @@
 \documentclass[a4paper,10pt]{article}
 %\documentclass[a4paper,10pt]{scrartcl}
 
-\usepackage{xltxtra}
-\usepackage{pbox}
-\usepackage{mathtools}
-\usepackage{amssymb}
-\usepackage{tabularx}
-\usepackage{siunitx}
-\usepackage[top=13pt, bottom=12pt, left=13pt, right=12pt]{geometry}
-% \setromanfont[Mapping=tex-text]{Linux Libertine O}
-% \setsansfont[Mapping=tex-text]{DejaVu Sans}
-% \setmonofont[Mapping=tex-text]{DejaVu Sans Mono}
-
-\title{}
-\author{}
-\date{}
-
-\let\oldcdot\cdot
-\let\oldbullet\bullet
-\let\oldvec\vec
-\let\olddot\dot
-\let\oldddot\ddot
-
-% \renewcommand{\cdot}{ }
-\renewcommand{\bullet}{\circ}
-% \renewcommand{\vec}{\mathbf}
-% \renewcommand{\dot}[1]{\frac{\mathrm{d}#1}{\mathrm{d}t}}
-% \renewcommand{\ddot}[1]{\frac{\mathrm{d^2}#1}{\mathrm{d}t^2}}
-% \renewcommand{\frac}[2]{#1 / #2}
-\newcommand{\cdotbis}{ }
-
-\setlength{\parindent}{0pt}
-\setlength{\parskip}{0pt}
+\input{common.tex}
 
 \begin{document}
-% \maketitle
 
 \begin{tabularx}{\textwidth}{ |X|X| }
 \hline