diff --git a/pymath/calculus/equation.py b/pymath/calculus/equation.py
index be773de..bbb6067 100644
--- a/pymath/calculus/equation.py
+++ b/pymath/calculus/equation.py
@@ -13,6 +13,12 @@ from .random_expression import RdExpression
 
 __all__ = ['Equation']
 
+def equals(new, old):
+    print("new -> ", new)
+    print("old -> ", old)
+    return new, old
+
+
 
 class Equation(object):
     """A calculus expression. Today it can andle only expression with numbers later it will be able to manipulate unknown"""
@@ -100,8 +106,7 @@ class Equation(object):
                 r = self.r_exp,
                 )
 
-    #@no_repetition(lambda x, y: (x[0] == y[0]) & (x[1] == y[1]))
-    @no_repetition()
+    @no_repetition(lambda x, y: (x[0] == y[0]) & (x[1] == y[1]), ['',''])
     def solve(self):
         r"""Solve the equation but yielding each steps
 
@@ -110,7 +115,6 @@ class Equation(object):
         ...    print(" = ".join([str(j) for j in i]))
         x + 123 = 0
         x + 123 - 123 = 0 - 123
-        x + 123 - 123 = 0 - 123
         x + 123 - 123 = -123
         x = -123
         >>> e = Equation("2x = x + 2")
@@ -118,7 +122,6 @@ class Equation(object):
         ...    print(" = ".join([str(j) for j in i]))
         2 x = x + 2
         2 x - x = x + 2 - x
-        2 x -  x = x + 2 -  x
         ( 2 - 1 ) x = x -  x + 2
         x = ( 1 - 1 ) x + 2
         x = 2
@@ -126,7 +129,7 @@ class Equation(object):
         >>> for i in e.solve():
         ...    print(" = ".join([str(j) for j in i]))
         2 x = 1
-        2 x \times 2 = 1 \times 2
+        \frac{ 2 x }{ 2 } = \frac{ 1 }{ 2 }
         \frac{ 2 }{ 2 } x = \frac{ 1 }{ 2 }
         x = \frac{ 1 }{ 2 }
         >>> e = Equation("2x + 1 = 4x + 2")
@@ -134,16 +137,13 @@ class Equation(object):
         ...    print(" = ".join([str(j) for j in i]))
         2 x + 1 = 4 x + 2
         2 x + 1 - 1 = 4 x + 2 - 1
-        2 x + 1 - 1 = 4 x + 2 - 1
-        2 x + 1 - 1 = 4 x + 2 - 1
         2 x = 4 x + 1
         2 x - 4 x = 4 x + 1 - 4 x
-        2 x - 4 x = 4 x + 1 - 4 x
         ( 2 - 4 ) x = 4 x - 4 x + 1
         -2 x = ( 4 - 4 ) x + 1
         -2 x = 1
-        -2 x \times ( -2 ) = 1 \times ( -2 )
-        \frac{ -2 }{ -2 } x = \frac{ 1 }{ -2 }
+        \frac{ -2 x }{ -2 } = \frac{ 1 }{ -2 }
+        \frac{ -2 }{ -2 } x = \frac{ -1 }{ 2 }
         x = \frac{ -1 }{ 2 }
         >>> e = Equation("2x + 3x + 1 = 4x + 2")
         >>> for i in e.solve():
@@ -152,11 +152,8 @@ class Equation(object):
         ( 2 + 3 ) x + 1 = 4 x + 2
         5 x + 1 = 4 x + 2
         5 x + 1 - 1 = 4 x + 2 - 1
-        5 x + 1 - 1 = 4 x + 2 - 1
-        5 x + 1 - 1 = 4 x + 2 - 1
         5 x = 4 x + 1
         5 x - 4 x = 4 x + 1 - 4 x
-        5 x - 4 x = 4 x + 1 - 4 x
         ( 5 - 4 ) x = 4 x - 4 x + 1
         x = ( 4 - 4 ) x + 1
         x = 1
diff --git a/pymath/calculus/step.py b/pymath/calculus/step.py
index bf6aa05..a431e82 100644
--- a/pymath/calculus/step.py
+++ b/pymath/calculus/step.py
@@ -74,7 +74,13 @@ class Step(Renderable):
             if self.postfix_tokens == other.postfix_tokens:
                 return True
         except AttributeError:
-            return False
+            pass
+
+        try:
+            if str(self).replace(' ', '') == str(other).replace(' ',''):
+                return True
+        except TypeError:
+            pass
 
         return False