diff --git a/mapytex/__init__.py b/mapytex/__init__.py
index 263836c..a6f7f80 100644
--- a/mapytex/__init__.py
+++ b/mapytex/__init__.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # encoding: utf-8
 
-from .calculus import Expression  # , Polynom, Fraction, random_str, txt, Equation
+from .calculus import Expression, Integer  # , Polynom, Fraction, random_str, txt, Equation
 
 # Expression.set_render('tex')
 
diff --git a/mapytex/calculus/API/__init__.py b/mapytex/calculus/API/__init__.py
index 7b77ce3..9e6153f 100644
--- a/mapytex/calculus/API/__init__.py
+++ b/mapytex/calculus/API/__init__.py
@@ -110,6 +110,7 @@ x^7
 """
 
 from .expression import Expression
+from .tokens.number import Integer
 
 if __name__ == "__main__":
     e = Expression.from_str("1+2/3/4/5")
diff --git a/mapytex/calculus/API/expression.py b/mapytex/calculus/API/expression.py
index 024d230..7179f11 100644
--- a/mapytex/calculus/API/expression.py
+++ b/mapytex/calculus/API/expression.py
@@ -108,9 +108,6 @@ class Expression(object):
         >>> e = Expression.from_str("2x + 1 + 5x")
         >>> e
         <Exp: 2x + 1 + 5x>
-        >>> e = Expression.from_str("3")
-        >>> e
-
         """
         t = Tree.from_str(string)
         if typing:
diff --git a/mapytex/calculus/__init__.py b/mapytex/calculus/__init__.py
index 91f40c9..81f27ad 100644
--- a/mapytex/calculus/__init__.py
+++ b/mapytex/calculus/__init__.py
@@ -30,7 +30,7 @@ Expression is the classe wich handle all calculus. It can randomly generate or i
 
 """
 
-from .API import Expression
+from .API import Expression, Integer
 
 __all__ = ["Expression"]