diff --git a/conf/bamc.conf b/conf/bamc.conf
index 8c0a7b2..017e65d 100644
--- a/conf/bamc.conf
+++ b/conf/bamc.conf
@@ -1,57 +1,58 @@
 #!/bin/bash
 
 # Workspace
 DIR_CONFIG='conf'
 DIR_QUESTIONS='questions'
 DIR_EXAMS='exams'
 DIR_PROJECTS='projects'
+DIR_COMMON='common'
 FILE_WORKSPACE_ROOT=".workspace_root"
 
 # Configuration dirs
 DIR_DATA=$(realpath $SPATH/../data)
 DIR_WORKSPACE_TEMPLATE=$DIR_DATA/workspace
 DIR_EXAM_TEMPLATES=$DIR_DATA/templates
 
 # Template
 DEFAULT_EXAM_TEMPLATE="default"
 FILE_PROJECT_BUILD="project_build_script.sh"
 
 # Configuration files
 FILE_AMC_OPTIONS='options.xml'
 
 # Output dirs
 DIR_PROJECTS='projects'
 DIR_SAMPLES='pdf-samples'
 DIR_CATALOGS='pdf-catalogs'
 DIR_BLANKS='pdf-blanks'
 DIR_PDFS='pdf-exams'
 DIR_STUDENTS='pdf-students'
 
 # Intput files
 FILE_SECTIONS='sections.conf'
 FILE_EXAM='exam.conf'
 FILE_STUDENTS='students.csv'
 
 # Variables
 EXTRA_STUDENTS=9
 PDFLATEX_RUNS=1
 
 return 0
 
 FILE_SAMPLE_CSV='sample.csv'
 FILE_EXTRA_CSV='extra.csv'
 FILE_BLANK_CSV='blank.csv'
 FILE_AMC_MAILING='mailing.xml'
 FILE_LIST_MAIN='list.tex'
 FILE_LIST_TSTART='start_tab.tex'
 FILE_LIST_TEND='end_tab.tex'
 
 # OUTPUT FILES
 FILE_RESULTS='raw'
 FILE_EMAILS_SCRIPT='send_emails.sh'
 FILE_LIST_ROWS='rows.tex'
 
 # VARIABLES
 DEFAULT_EMAIL='pierre-olivier.valles@epfl.ch'
 LIST_ROWS_PER_PAGE=50
 LIST_MAX_CHAR=30
diff --git a/data/templates/maths/base/style_professor.tex b/data/templates/maths/base/style_professor.tex
index f8f3295..de543ed 100644
--- a/data/templates/maths/base/style_professor.tex
+++ b/data/templates/maths/base/style_professor.tex
@@ -1,53 +1,6 @@
 %% New commands, professor specific
 
-\newcommand\RR{\mathbb{R}}
-\newcommand\PP{\mathbb{P}}
-\newcommand{\Col}{\mathop{\rm Col}\nolimits}
-\newcommand{\Nul}{\mathop{\rm Ker}\nolimits}
-\newcommand{\Lign}{\mathop{\rm Lig}\nolimits}
-
-\newcommand{\Span}{\mathop{\rm Vect}\nolimits}
-\renewcommand{\vec}[1]{\mathbf{#1}}
-\newcommand{\Poly}[1]{\mathbb{P}_#1}
-
-\newcommand{\Base}[1]{\left\{#1\right\}}
-
-\newcommand{\Vector}[1]{\left[
-    \begin{array}{c}
-      #1
-    \end{array}
-\right]
-}
-
-\newenvironment{Matrix}[1]{\left[
-    \begin{array}[r]{#1}}{
-    \end{array}
-\right]
-}
-
-% Some namenclature used:
-\newcommand{\dimension}{taille} % used for size of a matrix. usually dimension ou taille
-
 %% Questions %%%
 \baremeDefautS{b=3,m=-1}
 \baremeDefautM{b=2,m=0}
 
-\newcommand{\VERO}{
-  \bareme{b=1,m=-1}
-  \begin{choiceshoriz}[o]
-    \bonne{VRAI}
-    \mauvaise{FAUX}
-  \end{choiceshoriz}
-
-\medskip
-}
-
-\newcommand{\FALSO}{
-  \bareme{b=1,m=-1}
-  \begin{choiceshoriz}[o]
-    \mauvaise{VRAI}
-    \bonne{FAUX}
-  \end{choiceshoriz}
-
-\medskip
-}
diff --git a/data/templates/maths/de/true-false.tex b/data/templates/maths/de/true-false.tex
index c06d683..ffe6ddb 100644
--- a/data/templates/maths/de/true-false.tex
+++ b/data/templates/maths/de/true-false.tex
@@ -1,23 +1,43 @@
 %% TRUE / FALSE commands - GERMAN
 
 \AMCtext{draft}{ENTWURF}
 
 \newcommand{\TRUE}{
   \bareme{b=1,m=-1}
   \begin{choiceshoriz}[o]
     \bonne{WAHR}
     \mauvaise{FALSCH}
   \end{choiceshoriz}
 \medskip
 }
 
 \newcommand{\FALSE}{
   \bareme{b=1,m=-1}
   \begin{choiceshoriz}[o]
     \mauvaise{WAHR}
     \bonne{FALSCH}
   \end{choiceshoriz}
 \medskip
 }
 
-%% End of file
\ No newline at end of file
+% For compat. reasons...
+
+\newcommand{\VERO}{
+  \bareme{b=1,m=-1}
+  \begin{choiceshoriz}[o]
+    \bonne{WAHR}
+    \mauvaise{FALSCH}
+  \end{choiceshoriz}
+\medskip
+}
+
+\newcommand{\FALSO}{
+  \bareme{b=1,m=-1}
+  \begin{choiceshoriz}[o]
+    \mauvaise{WAHR}
+    \bonne{FALSCH}
+  \end{choiceshoriz}
+\medskip
+}
+
+%% End of file
diff --git a/data/templates/maths/en/true-false.tex b/data/templates/maths/en/true-false.tex
index 9dbb04a..32a9677 100644
--- a/data/templates/maths/en/true-false.tex
+++ b/data/templates/maths/en/true-false.tex
@@ -1,21 +1,41 @@
 %% TRUE / FALSE commands - ENGLISH
 
 \newcommand{\TRUE}{
   \bareme{b=1,m=-1}
   \begin{choiceshoriz}[o]
     \bonne{TRUE}
     \mauvaise{FALSE}
   \end{choiceshoriz}
 \medskip
 }
 
 \newcommand{\FALSE}{
   \bareme{b=1,m=-1}
   \begin{choiceshoriz}[o]
     \mauvaise{TRUE}
     \bonne{FALSE}
   \end{choiceshoriz}
 \medskip
 }
 
-%% End of file
\ No newline at end of file
+% For compat. reasons...
+
+\newcommand{\VERO}{
+  \bareme{b=1,m=-1}
+  \begin{choiceshoriz}[o]
+    \bonne{TRUE}
+    \mauvaise{FALSE}
+  \end{choiceshoriz}
+\medskip
+}
+
+\newcommand{\FALSO}{
+  \bareme{b=1,m=-1}
+  \begin{choiceshoriz}[o]
+    \mauvaise{TRUE}
+    \bonne{FALSE}
+  \end{choiceshoriz}
+\medskip
+}
+
+%% End of file
diff --git a/data/templates/maths/fr/true-false.tex b/data/templates/maths/fr/true-false.tex
index 753487d..0bd11b2 100644
--- a/data/templates/maths/fr/true-false.tex
+++ b/data/templates/maths/fr/true-false.tex
@@ -1,21 +1,41 @@
 %% TRUE / FALSE commands - FRENCH
 
 \newcommand{\TRUE}{
   \bareme{b=1,m=-1}
   \begin{choiceshoriz}[o]
     \bonne{VRAI}
     \mauvaise{FAUX}
   \end{choiceshoriz}
 \medskip
 }
 
 \newcommand{\FALSE}{
   \bareme{b=1,m=-1}
   \begin{choiceshoriz}[o]
     \mauvaise{VRAI}
     \bonne{FAUX}
   \end{choiceshoriz}
 \medskip
 }
 
-%% End of file
\ No newline at end of file
+% For compat. reasons...
+
+\newcommand{\VERO}{
+  \bareme{b=1,m=-1}
+  \begin{choiceshoriz}[o]
+    \bonne{VRAI}
+    \mauvaise{FAUX}
+  \end{choiceshoriz}
+\medskip
+}
+
+\newcommand{\FALSO}{
+  \bareme{b=1,m=-1}
+  \begin{choiceshoriz}[o]
+    \mauvaise{VRAI}
+    \bonne{FAUX}
+  \end{choiceshoriz}
+\medskip
+}
+
+%% End of file
diff --git a/data/templates/maths/project_build_script.sh b/data/templates/maths/project_build_script.sh
index 082bfce..fc6082c 100644
--- a/data/templates/maths/project_build_script.sh
+++ b/data/templates/maths/project_build_script.sh
@@ -1,214 +1,234 @@
 #!/bin/bash
 
 # This part is specific to the template.
 # Entry point from bamc: build_project $exam
 # $exam: name of the exam to build
 #
 # Useful variable
 # ---------------
 # DIR_WORKSPACE     [current workspace dir (absolute)]
 # DIR_PROJECTS      [projects target directory]
 # DIR_EXAMS         [exams'directory in workspace] e.g. $DIR_WORKSPACE/$DIR_EXAMS/$exam
 # DIR_PROJECTS      [projects's directory in workspace]
 # DIR_EXAM_TEMPLATE [directory of the exam template in use]
 # FILE_STUDENTS
 # ...
 # see 'conf/bamc.conf' for full reference
 #
 # Useful functions
 # ----------------
 # verbose "text"
 # debug "text"
 # get_lang $exam
 # ...
 # see 'lib/bash/*.sh' files for full reference
 
 function build_project() {
 	local exam=$1 lang=$(get_lang $exam)
 	assert_exam $exam
 	verbose "Project '$exam' uses '$lang' language"
 
 	if [ $? -eq 1 ]; then return 1; fi
 	verbose "Building AMC project for '$exam' in workspace '$DIR_WORKSPACE'..."
 
 	# Project structure
 	build_amc_project $exam
 	if [ $? -ne 0 ]; then error "Could not build AMC project :("; return 1; fi
 
 	# Build LaTeX sections
 	build_sections $exam $lang
 	if [ $? -ne 0 ]; then error "Could not build project sections :("; return 1; fi
 
 	# Import LaTeX files
 	import_tex_files $exam $lang
 	if [ $? -ne 0 ]; then error "Could not import LaTeX files :("; return 1; fi
 
 	# Import local LaTeX files
 	override_tex_files $exam
 	if [ $? -ne 0 ]; then error "Could not override LaTeX files :("; return 1; fi
 
 	# Customize LaTeX file
 	customize_tex_files $exam $lang
 	if [ $? -ne 0 ]; then error "Could not customize LaTeX files :("; return 1; fi
 
 	# Import media files
 	add_media_files $exam
 	if [ $? -ne 0 ]; then error "Could not import media files :("; return 1; fi
 
 	# Build student list file
 	import_student_file $exam
 	if [ $? -ne 0 ]; then error "Could not create student list :("; return 1; fi
 
 	return 0
 }
 
 function import_student_file() {
   	verbose "Customizing student files"
 	local project=$DIR_WORKSPACE/$DIR_PROJECTS/$1
 	local exam=$DIR_WORKSPACE/$DIR_EXAMS/$1
   	local lang=$2
 
 	local FILE=$exam/$FILE_STUDENTS
 	check_file_exists $FILE
 	if [ $? -ne 0 ]; then return 1; fi
 
 	cp $FILE $project/$FILE_STUDENTS
   
 	# Add extra students
 	local nb IFS=$'\n'
 	local id=$(tail -n 1 $project/$FILE_STUDENTS | cut -d ',' -f 1)
 	local sample=$(head -n 1 $DIR_EXAM_TEMPLATE/csv/extra.csv)
 	nb=0
 	while [ $nb -lt $EXTRA_STUDENTS ]; do
 		((nb++))
 		((id++))
 		echo $sample |\
 		sed "s/#NB#/$nb/g" |\
 		sed "s/#ID#/$id/g" |\
 		sed "s/#SCIPER#/FAKE-$nb/g" |\
 		sed "s/#EMAIL#/$DEFAULT_EMAIL/g" |\
 		sed "s/#SEMESTER#/$SEMESTER/g" >> $project/$FILE_STUDENTS
 	done
 	return 0
 }
 
 
 function add_media_files() {
   	verbose "Importing media files"
 	local project=$DIR_WORKSPACE/$DIR_PROJECTS/$1
 	cp $DIR_EXAM_TEMPLATE/media/* $project/media/
 }
 
 
 function customize_tex_files() {
   	verbose "Customizing LaTeX files"
 	local project=$DIR_WORKSPACE/$DIR_PROJECTS/$1
 	local exam=$DIR_WORKSPACE/$DIR_EXAMS/$1
   	local lang=$2
 
 	local replace IFS=$'\n'
 	local FILE=$exam/$FILE_EXAM
 	check_file_exists $FILE
 	if [ $? -ne 0 ]; then return 1; fi
   
 	# professor.tex
 	local prof_file=$project/professor.tex
 	check_file_exists $prof_file
 	if [ $? -ne 0 ]; then return 1; fi
 	for replace in $(cat $FILE); do
 		replace_in_file "#$(echo $replace | cut -d ':' -f 1)#" "$(echo $replace | cut -d ':' -f 2-)" $prof_file
 	done
   
 	# exam.tex
 	replace_in_file "#LANG#" $(echo $lang | tr '[a-z]' '[A-Z]') $project/exam.tex
-  
+
+	# Add extra_packages.tex file
+	if [ -r $project/common_packages.tex ]; then
+		replace_in_file '% #COMMON_PACKAGES#' '\\input{./common_packages.tex}' $project/exam.tex
+	fi
+	# Add extra_packages.tex file
+	if [ -r $project/common_commands.tex ]; then
+		replace_in_file '% #COMMON_COMMANDS#' '\\input{./common_commands.tex}' $project/exam.tex
+	fi
+
 	# Add extra_section.tex file
-	if [ -r $exam/extra_section.tex ]; then
+	if [ -r $project/extra_section.tex ]; then
 		replace_in_file '% #EXTRA_SECTION#' '\\input{./extra_section.tex}' $project/exam.tex
 	fi
 	# Add extra_packages.tex file
-	if [ -r $exam/extra_packages.tex ]; then
+	if [ -r $project/extra_packages.tex ]; then
 		replace_in_file '% #EXTRA_PACKAGES#' '\\input{./extra_packages.tex}' $project/exam.tex
 	fi
 	# Add extra_packages.tex file
-	if [ -r $exam/extra_commands.tex ]; then
+	if [ -r $project/extra_commands.tex ]; then
 		replace_in_file '% #EXTRA_COMMANDS#' '\\input{./extra_commands.tex}' $project/exam.tex
 	fi
 
 	return 0
 }
 
 function override_tex_files() {
-  	verbose "Overriding LaTeX files (if needed)"
+  	verbose "Importing supplementary LaTeX files"
+	local common=$DIR_WORKSPACE/$DIR_COMMON/
 	local exam=$DIR_WORKSPACE/$DIR_EXAMS/$1
 	local project=$DIR_WORKSPACE/$DIR_PROJECTS/$1
 	local f
+
+	# Common
+	for f in $(find $common/ -type f -name '*.tex'); do
+		verbose "- Common LaTeX file found: $f"
+	done
+	find $common/ -type f -name '*.tex' -exec cp {} $project/ \;
+
+	# Extra
 	for f in $(find $exam/ -type f -name '*.tex'); do
-		verbose "- LaTeX override file found: $f"
+		verbose "- Extra LaTeX file found: $f"
 	done
 	find $exam/ -type f -name '*.tex' -exec cp {} $project/ \;
+
+	return 0
 }
 
 function import_tex_files() {
   	verbose "Importing LaTeX files"
 	local project=$DIR_WORKSPACE/$DIR_PROJECTS/$1
   	local lang=$2
 	cp $DIR_EXAM_TEMPLATE/base/* $project/
 	cp $DIR_EXAM_TEMPLATE/$lang/* $project/
 	return 0
 }
 
 function build_amc_project() {
 	local project=$DIR_WORKSPACE/$DIR_PROJECTS/$1
 	verbose "Creating AMC project structure"
 	mkdir -p $project/cr/corrections/jpg
 	mkdir -p $project/cr/corrections/pdf
 	mkdir -p $project/cr/diagnostic
 	mkdir -p $project/cr/zooms
 	mkdir -p $project/data
 	mkdir -p $project/exports
 	mkdir -p $project/scans
 	mkdir -p $project/copies
 	mkdir -p $project/media
 	cp $DIR_EXAM_TEMPLATE/config/$FILE_AMC_OPTIONS $project/$FILE_AMC_OPTIONS
 	return $?
 }
 
 function build_sections() {
 	local project=$DIR_WORKSPACE/$DIR_PROJECTS/$1
 	local exam=$DIR_WORKSPACE/$DIR_EXAMS/$1
 	local lang=$2
 
 	local question_file question section_file section
 	local IFS=$'\n' FILE=$exam/$FILE_SECTIONS
 
 	verbose "Importing questions"
 	check_file_exists $FILE
 	if [ $? -ne 0 ]; then return 1; fi
 
 	local section_num=0
 	rm -f $project/sections.tex $project/random-sections.tex
 	for section in $(cat $FILE); do
 		((section_num++))
 		section_file=$project/section_${section_num}.tex
 		rm -f $section_file
 		for question in $(echo $section | tr ',' '\n'); do
 			verbose "Adding $question to section $section_file...";
 			question_file=$DIR_WORKSPACE/$DIR_QUESTIONS/$lang/$question
 			check_file_exists $question_file
 			if [ $? -ne 0 ]; then return 1; fi
 			echo "%% From $lang/$question =======================================" >> $section_file
 			echo '\element{section'$section_num'}{' >> $section_file
 			cat $question_file >> $section_file
 			echo '}' >> $section_file
 		done
 		echo "\input{./section_${section_num}.tex}" >> $project/sections.tex
 		echo "\input{./header_${section_num}.tex}
 \melangegroupe{section${section_num}}
 \restituegroupe{section${section_num}}
 " >> $project/random-sections.tex
 	done
 	return 0
 }
 
 # EOF
diff --git a/data/workspace/common/common_commands.tex.sample b/data/workspace/common/common_commands.tex.sample
new file mode 100644
index 0000000..a35fd38
--- /dev/null
+++ b/data/workspace/common/common_commands.tex.sample
@@ -0,0 +1,6 @@
+%% Specific commands for Skel teacher (EXAMPLE)
+
+\newcommand{\R}{\mathbb{R}}
+\newcommand{\Q}{\mathbb{Q}}
+\newcommand{\N}{\mathbb{N}}
+\newcommand{\Z}{\mathbb{Z}}
diff --git a/data/workspace/common/common_packages.tex.sample b/data/workspace/common/common_packages.tex.sample
new file mode 100644
index 0000000..4b96955
--- /dev/null
+++ b/data/workspace/common/common_packages.tex.sample
@@ -0,0 +1,4 @@
+%% Extra packages for all exams
+
+% none
+