diff --git a/pymath/calculus/operator/operator.py b/pymath/calculus/operator/operator.py
index f1044f8..5dd6897 100644
--- a/pymath/calculus/operator/operator.py
+++ b/pymath/calculus/operator/operator.py
@@ -67,20 +67,28 @@ class Operator():
         :*args: Operands for this operation
         :returns: String with operator and his operands
 
-        >>> op.mul.__txt__('1','2')
+        >>> from .mul import Mul
+        >>> mul= Mul()
+        >>> from .add import Add
+        >>> add = Add()
+        >>> from .sub import Sub
+        >>> sub = Sub()
+        >>> from .sub1 import Sub1
+        >>> sub1 = Sub1()
+        >>> mul.__txt__('1','2')
         '1 * 2'
-        >>> op.add.__txt__('1','2')
+        >>> add.__txt__('1','2')
         '1 + 2'
-        >>> f = save_mainOp('2 + 3',op.add)
-        >>> op.mul.__txt__(f, '4')
+        >>> f = save_mainOp('2 + 3',add)
+        >>> mul.__txt__(f, '4')
         '( 2 + 3 ) * 4'
-        >>> f = save_mainOp('-3',op.sub1)
-        >>> op.sub1.__txt__(f)
+        >>> f = save_mainOp('-3',sub1)
+        >>> sub1.__txt__(f)
         '- ( -3 )'
-        >>> op.sub1.__txt__('-3')
+        >>> sub1.__txt__('-3')
         '- ( -3 )'
-        >>> f = save_mainOp('2 + 3',op.add)
-        >>> op.sub1.__txt__(f)
+        >>> f = save_mainOp('2 + 3',add)
+        >>> sub1.__txt__(f)
         '- ( 2 + 3 )'
         """
         return self._render(self.txt, *args)
@@ -91,20 +99,28 @@ class Operator():
         :*args: Operands for this operation
         :returns: String with operator and his operands
 
-        >>> op.mul.__tex__('1','2')
+        >>> from .mul import Mul
+        >>> mul= Mul()
+        >>> from .add import Add
+        >>> add = Add()
+        >>> from .sub import Sub
+        >>> sub = Sub()
+        >>> from .sub1 import Sub1
+        >>> sub1 = Sub1()
+        >>> mul.__tex__('1','2')
         '1 \\\\times 2'
-        >>> op.add.__tex__('1','2')
+        >>> add.__tex__('1','2')
         '1 + 2'
-        >>> f = save_mainOp('2 + 3',op.add)
-        >>> op.mul.__tex__(f, '4')
+        >>> f = save_mainOp('2 + 3',add)
+        >>> mul.__tex__(f, '4')
         '( 2 + 3 ) \\\\times 4'
-        >>> f = save_mainOp('-3',op.sub1)
-        >>> op.sub1.__tex__(f)
+        >>> f = save_mainOp('-3',sub1)
+        >>> sub1.__tex__(f)
         '- ( -3 )'
-        >>> op.sub1.__tex__('-3')
+        >>> sub1.__tex__('-3')
         '- ( -3 )'
-        >>> f = save_mainOp('2 + 3',op.add)
-        >>> op.sub1.__tex__(f)
+        >>> f = save_mainOp('2 + 3',add)
+        >>> sub1.__tex__(f)
         '- ( 2 + 3 )'
         """
         return self._render(self.tex, *args)
@@ -115,19 +131,27 @@ class Operator():
         :*args: Operands for this operation
         :returns: list with the operator surrounded by operands
 
-        >>> op.mul.__p2i__(1,2)
-        [1, '*', 2]
-        >>> f = save_mainOp([2, op.add, 3],op.add)
-        >>> op.mul.__p2i__(f, 4)
-        ['(', 2, '+', 3, ')', '*', 4]
-        >>> f = save_mainOp([op.sub1, 3],op.sub1)
-        >>> op.sub1.__p2i__(f)
-        ['-', '(', '-', 3, ')']
-        >>> op.sub1.__p2i__(-3)
-        ['-', '(', -3, ')']
-        >>> f = save_mainOp([2, op.add, 3],op.add)
-        >>> op.sub1.__p2i__(f)
-        ['-', '(', 2, '+', 3, ')']
+        >>> from .mul import Mul
+        >>> mul= Mul()
+        >>> from .add import Add
+        >>> add = Add()
+        >>> from .sub import Sub
+        >>> sub = Sub()
+        >>> from .sub1 import Sub1
+        >>> sub1 = Sub1()
+        >>> mul.__p2i__(1,2)
+        [1, *, 2]
+        >>> f = save_mainOp([2, add, 3],add)
+        >>> mul.__p2i__(f, 4)
+        ['(', 2, +, 3, ')', *, 4]
+        >>> f = save_mainOp([sub1, 3],sub1)
+        >>> sub1.__p2i__(f)
+        [-, '(', -, 3, ')']
+        >>> sub1.__p2i__(-3)
+        [-, '(', -3, ')']
+        >>> f = save_mainOp([2, add, 3],add)
+        >>> sub1.__p2i__(f)
+        [-, '(', 2, +, 3, ')']
         """
         if self.arity == 1:
             op1 = self.l_parenthesis(args[0])
@@ -201,35 +225,6 @@ def save_mainOp(obj, mainOp):
     return Fake(obj)
 
 
-if __name__ == '__main__':
-    #print(op.add.__tex__('1','2'))
-    #print(op.mul.__tex__('1','2'))
-    #print(op.sub.__tex__('1','2'))
-    #f = save_mainOp('2 + 3',op.add)
-    #print(op.mul.__txt__(f, '4'))
-    #f = save_mainOp('-3',op.sub1)
-    #print(op.sub1.__txt__(f))
-    #print(op.sub1.__txt__('-3'))
-    #f = save_mainOp('2 + 3',op.add)
-    #print(op.sub1.__txt__(f))
-
-    #from .fraction import Fraction
-    #f = Fraction(1, 2)
-    #print(op.add.__txt__(f.__txt__(),'2'))
-    #print(op.add.__tex__(f.__tex__(),'2'))
-
-    #print("\t op.can_be_operator('+') :" + str(op.can_be_operator('+')))
-    #print("\t op.can_be_operator('t') :" + str(op.can_be_operator('t')))
-
-    print("op.sub.__dict__ -> ", op.sub.__dict__)
-    print(op.sub == op.sub1)
-    #import doctest
-    #doctest.testmod()
-
-
-
-
-
 # -----------------------------
 # Reglages pour 'vim'
 # vim:set autoindent expandtab tabstop=4 shiftwidth=4:
diff --git a/pymath/calculus/operator/operator_set.py b/pymath/calculus/operator/operator_set.py
index c31137e..7a69c97 100644
--- a/pymath/calculus/operator/operator_set.py
+++ b/pymath/calculus/operator/operator_set.py
@@ -82,6 +82,11 @@ class Operator_set(object):
         >>> op.store_operator(Add())
         >>> op._operators
         {('+', 2): 'add'}
+        >>> a = op.add
+        >>> a
+        +
+        >>> a.tex
+        '{op1} + {op2}'
         >>> op.store_operator("+")
         Traceback (most recent call last): 
             ...