diff --git a/mapytex/calculus/API/__init__.py b/mapytex/calculus/API/__init__.py
index 6c50b5b..837d669 100644
--- a/mapytex/calculus/API/__init__.py
+++ b/mapytex/calculus/API/__init__.py
@@ -81,15 +81,20 @@ x^7
 (2 + 3) * x + 2
 5x + 2
 
->>> e = Expression.from_str("2x^2+2x+3x")
+>>> e = Expression.from_str("1+2x^2+3x+4+5x")
 >>> e_simplified = e.simplify()
 >>> print(e_simplified)
-2x^2 + 5x
+2x^2 + 5 + 8x
 >>> for s in e_simplified.explain():
 ...    print(s)
-2x^2 + 2x + 3x
-2x^2 + (2 + 3) * x
-2x^2 + 5x
+1 + 2x^2 + 3x + 4 + 5x
+2x^2 + 3x + 1 + 4 + 5x
+3x + 5 + 2x^2 + 5x
+2x^2 + 3x + 5x + 5
+2x^2 + (3 + 5) * x + 5
+2x^2 + 5 + 8x
+
+
 """
 
 from .expression import Expression
diff --git a/mapytex/calculus/API/expression.py b/mapytex/calculus/API/expression.py
index 01b91fa..90c7f21 100644
--- a/mapytex/calculus/API/expression.py
+++ b/mapytex/calculus/API/expression.py
@@ -202,13 +202,14 @@ class Expression(object):
         >>> f._ancestor
         <Exp: 2 + 12>
         """
-        if optimize:
-            opt_exp = self._optimize()
-        else:
-            opt_exp = self
+        typed_exp = self._typing()
 
-        typed_exp = opt_exp._typing()
-        comp_exp = typed_exp._compute()
+        if optimize:
+            opt_exp = typed_exp._optimize()
+        else:
+            opt_exp = typed_exp
+
+        comp_exp = opt_exp._compute()
 
         if typed_exp == comp_exp:
             typed_exp.set_ancestor(self._ancestor)