diff --git a/misc/expression.py b/misc/expression.py
index 9ce2e8f..6050eb2 100644
--- a/misc/expression.py
+++ b/misc/expression.py
@@ -1,10 +1,10 @@
-import re
 from math import cos, sin, exp, sqrt
+from misc.util import isNumber
 
 class Expression:
 
     def __init__(self, val=None, gauche=None, droite=None):
-        if Token.isNumber(val) and (gauche != None or droite != None):
+        if isNumber(val) and (gauche != None or droite != None):
             raise AttributeError("gauche et droite ne peuvent pas exister si val est un nombre")
         self.val = val
         self.gauche = gauche
@@ -34,37 +34,6 @@ class Expression:
             return float(self.val)
 
     def __str__(self):
-        if Token.isNumber(self.val):
+        if isNumber(self.val):
             return str(self.val)
         return "(" + str(self.gauche.__str__()) + str(self.val) + str(self.droite.__str__()) + ")"
-
-
-class Token:
-    NUMBER = 0
-    OPERATOR = 1
-    PARENTHESE = 2
-    FUNCTION = 3
-
-    @staticmethod
-    def isChar(n):
-        return re.match(r'[a-z]', str(n)) is not None
-    
-    @staticmethod
-    def isNumber(n):
-        return re.match(r'\d+', str(n)) is not None
-
-    @staticmethod
-    def getPrecedence(tok):
-        if tok == "(" or tok == "" or tok == "^":
-            return 4
-        elif tok == "*" or tok == "/":
-            return 3
-        elif tok == "+" or tok == "-":
-            return 2
-
-    def __init__(self, type, val):
-        self.type = type
-        self.val = val
-
-    def __str__(self):
-        return self.val
\ No newline at end of file
diff --git a/misc/parser.py b/misc/parser.py
index 4365274..638e094 100644
--- a/misc/parser.py
+++ b/misc/parser.py
@@ -1,6 +1,8 @@
-from misc.expression import Token, Expression
+from misc.expression import Expression
+from misc.tokenizer import Token
 from lib.Pile import Pile_chaine as Pile
 from lib.File import File_chaine as File
+from misc.util import getPrecedence
 
 def shutting_yard(tokens: list) -> File:
     output = File()
@@ -11,7 +13,7 @@ def shutting_yard(tokens: list) -> File:
         elif token.type == Token.FUNCTION:
             opertator.empiler(token)
         elif token.type == Token.OPERATOR:
-            while (not opertator.est_vide() and opertator.sommet().val != "(") and (Token.getPrecedence(opertator.sommet().val) > Token.getPrecedence(token.val) or (Token.getPrecedence(token.val) == Token.getPrecedence(opertator.sommet().val) and token.val != "^")):
+            while (not opertator.est_vide() and opertator.sommet().val != "(") and (getPrecedence(opertator.sommet().val) > getPrecedence(token.val) or (getPrecedence(token.val) == getPrecedence(opertator.sommet().val) and token.val != "^")):
                 output.enfiler(opertator.depiler())
             opertator.empiler(token)
         elif token.val == "(":
diff --git a/misc/tokenizer.py b/misc/tokenizer.py
index 818dc48..f412348 100644
--- a/misc/tokenizer.py
+++ b/misc/tokenizer.py
@@ -1,13 +1,13 @@
-from misc.expression import Token
+from misc.util import isChar, isNumber
 
 def tokenize(text: str) -> list:
     buffer_num = ""
     buffer_func = ""
     tokens = []
     for char in text:
-        if Token.isChar(char):
+        if isChar(char):
             buffer_func += char
-        elif Token.isNumber(char) or char == ".":
+        elif isNumber(char) or char == ".":
             buffer_num += char
         else:
             if buffer_num != "":
@@ -24,4 +24,17 @@ def tokenize(text: str) -> list:
         tokens.append(Token(Token.NUMBER, buffer_num))
     if buffer_func != "":
         tokens.append(Token(Token.FUNCTION, buffer_func))
-    return tokens
\ No newline at end of file
+    return tokens
+
+class Token:
+    NUMBER = 0
+    OPERATOR = 1
+    PARENTHESE = 2
+    FUNCTION = 3
+
+    def __init__(self, type, val):
+        self.type = type
+        self.val = val
+
+    def __str__(self):
+        return self.val
\ No newline at end of file
diff --git a/misc/util.py b/misc/util.py
new file mode 100644
index 0000000..9d8601c
--- /dev/null
+++ b/misc/util.py
@@ -0,0 +1,15 @@
+import re
+
+def isChar(n):
+    return re.match(r'[a-z]', str(n)) is not None
+
+def isNumber(n):
+    return re.match(r'\d+', str(n)) is not None
+
+def getPrecedence(tok):
+    if tok == "(" or tok == "" or tok == "^":
+        return 4
+    elif tok == "*" or tok == "/":
+        return 3
+    elif tok == "+" or tok == "-":
+        return 2
\ No newline at end of file