diff --git a/pymath/explicable.py b/pymath/explicable.py
index 360235d..4db74b3 100644
--- a/pymath/explicable.py
+++ b/pymath/explicable.py
@@ -25,6 +25,7 @@ class Renderable(object):
 
         The default temporary render is Expression in order to perform calculus inside numbers
 
+        >>> from .expression import Expression
         >>> exp = Expression("2*3/5")
         >>> print(exp)
         2 \\times \\frac{ 3 }{ 5 }
diff --git a/pymath/expression.py b/pymath/expression.py
index 2f63b3d..08ec98b 100644
--- a/pymath/expression.py
+++ b/pymath/expression.py
@@ -42,10 +42,10 @@ class Expression(Explicable):
         >>> with Expression.tmp_render():
         ...     for i in exp.simplify().explain():
         ...         i
-        < <class '__main__.Expression'> [2, 3, 5, '/', '*'] >
-        < <class '__main__.Expression'> [2, < Fraction 3 / 5>, '*'] >
-        < <class '__main__.Expression'> [2, < Fraction 3 / 5>, '*'] >
-        < <class '__main__.Expression'> [6, 5, '/'] >
+        < <class 'pymath.expression.Expression'> [2, 3, 5, '/', '*'] >
+        < <class 'pymath.expression.Expression'> [2, < Fraction 3 / 5>, '*'] >
+        < <class 'pymath.expression.Expression'> [2, < Fraction 3 / 5>, '*'] >
+        < <class 'pymath.expression.Expression'> [6, 5, '/'] >
         >>> from .render import txt
         >>> with Expression.tmp_render(txt):
         ...     for i in exp.simplify().explain():
diff --git a/pymath/str2tokens.py b/pymath/str2tokens.py
index ad340d7..7899a03 100644
--- a/pymath/str2tokens.py
+++ b/pymath/str2tokens.py
@@ -12,7 +12,7 @@ def str2tokens(exp):
     >>> str2tokens('2*3+4')
     [2, 3, '*', 4, '+']
     >>> str2tokens('2x+4')
-    [2, < Polynom [0, 1]>, '*', 1, '+']
+    [2, < Polynom [0, 1]>, '*', 4, '+']
     """
     in_tokens = str2in_tokens(exp)
     post_tokens = in2post_fix(in_tokens)