diff --git a/generate_bilan/__init__.py b/generate_bilan/__init__.py
index e69de29..dd9b638 100644
--- a/generate_bilan/__init__.py
+++ b/generate_bilan/__init__.py
@@ -0,0 +1,9 @@
+#!/usr/bin/env python
+# encoding: utf-8
+
+from generate_bilan import generate_bilan
+
+# -----------------------------
+# Reglages pour 'vim'
+# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
+# cursor: 16 del 
diff --git a/generate_bilan/__main__.py b/generate_bilan/__main__.py
new file mode 100644
index 0000000..2c27163
--- /dev/null
+++ b/generate_bilan/__main__.py
@@ -0,0 +1,17 @@
+#!/usr/bin/env python
+# encoding: utf-8
+
+from generate_bilan import generate_bilan
+import optparse
+
+parser = optparse.OptionParser()
+parser.add_option("-c","--classe",action="store",type="string",dest="classe", help="The classe")
+parser.add_option("-e","--evaluation",action="store",type="string",dest="ds_name", help="The evaluation name.")
+(options, args) = parser.parse_args()
+
+build_bilan(options.classe, options.ds_name)
+
+# -----------------------------
+# Reglages pour 'vim'
+# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
+# cursor: 16 del 
diff --git a/generate_bilan/generate_bilan.py b/generate_bilan/generate_bilan.py
index f363d08..8af5d25 100755
--- a/generate_bilan/generate_bilan.py
+++ b/generate_bilan/generate_bilan.py
@@ -1,12 +1,10 @@
 #!/usr/bin/env python
 # encoding: utf-8
 
-from extract import extract_flat_marks, get_class_ws
-from df_marks_manip import digest_flat_df, students_pov
-from opytex import texenv
+from notes_tools import extract_flat_marks, get_class_ws, digest_flat_df, students_pov
+from generate_bilan.texenv import texenv
 import pandas as pd
 import numpy as np
-import optparse
 import xlrd
 
 notStudent = ["Trimestre", "Nom", "Date", "Exercice", "Question", "Competence", "Domaine", "Commentaire", "Bareme", "Niveau"]
@@ -84,7 +82,7 @@ def feed_bilan(target, datas, template = "./tpl_bilan.tex"):
         f.write(bilan.render(**datas))
     print("{} est construit! Ya plus qu'à compiler!".format(target))
 
-def build_bilan(classe, ds_name):
+def generate_bilan(classe, ds_name):
     ws = get_class_ws(classe)
 
     flat_df = extract_flat_marks(ws)
@@ -103,14 +101,6 @@ def build_bilan(classe, ds_name):
     feed_bilan(target, datas)
 
 
-if __name__ == "__main__":
-    parser = optparse.OptionParser()
-    parser.add_option("-c","--classe",action="store",type="string",dest="classe", help="The classe")
-    parser.add_option("-e","--evaluation",action="store",type="string",dest="ds_name", help="The evaluation name.")
-    (options, args) = parser.parse_args()
-
-    build_bilan(options.classe, options.ds_name)
-
 
 # -----------------------------
 # Reglages pour 'vim'
diff --git a/generate_bilan/texenv.py b/generate_bilan/texenv.py
new file mode 100644
index 0000000..4a35e68
--- /dev/null
+++ b/generate_bilan/texenv.py
@@ -0,0 +1,53 @@
+#!/usr/bin/env python
+# encoding: utf-8
+
+import jinja2, os
+
+__all__ = ["texenv"]
+
+# Definition of jinja syntax for latex
+texenv = jinja2.Environment(
+    block_start_string = '\Block{',
+    # Gros WTF!! Si on le met en maj ça ne marche pas alors que c'est en maj dans le template...
+    block_end_string = '}',
+    variable_start_string = '\Var{',
+    variable_end_string = '}',
+    loader = jinja2.FileSystemLoader(os.path.abspath('.')),
+    extensions = ['jinja2.ext.do']
+)
+
+# Filters
+
+def do_calculus(steps, name = "A", sep = "=", end = "", joining = " \\\\ \n"):
+    """Display properly the calculus
+
+    Generate this form string:
+    "name & sep & a_step end joining"
+
+    :param steps: list of steps
+    :returns: latex string ready to be endbeded
+
+
+    """
+
+    ans = joining.join([name + " & " + sep + " & " + str(s) + end for s in steps])
+    return ans
+
+texenv.filters['calculus'] = do_calculus
+
+from random import shuffle
+texenv.filters['shuffle'] = shuffle
+
+
+
+if __name__ == '__main__':
+    from pymath.expression import Expression
+    exp = Expression("2/4 + 18")
+    print(do_calculus(exp.simplify()))
+
+
+
+# -----------------------------
+# Reglages pour 'vim'
+# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
+# cursor: 16 del 
diff --git a/notes_tools/__init__.py b/notes_tools/__init__.py
index e69de29..c6975c2 100644
--- a/notes_tools/__init__.py
+++ b/notes_tools/__init__.py
@@ -0,0 +1,13 @@
+#!/usr/bin/env python
+# encoding: utf-8
+
+
+from notes_tools.extract import extract_flat_marks, get_class_ws
+from notes_tools.df_marks_manip import digest_flat_df, students_pov
+
+
+
+# -----------------------------
+# Reglages pour 'vim'
+# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
+# cursor: 16 del