Typo fixes

doc/tutorial/extending_theano.txt

@@ -451,7 +451,7 @@ tutorial :ref:`Extending Theano<extending>`
 See :ref:`metadocumentation`, for some information on how to generate
 the documentation.
 
-Here is an example how to add docstring to an class.
+Here is an example how to add docstring to a class.
 
 .. code-block:: python
 
@@ -462,7 +462,7 @@ Here is an example how to add docstring to an class.
 
     :param x: input tensor.
 
-    :return: a tensor of the shape shape and dtype as the input with all
+    :return: a tensor of the same shape and dtype as the input with all
         values doubled.
 
     :note:
@@ -475,7 +475,8 @@ Here is an example how to add docstring to an class.
     .. versionadded:: 0.6
     """
 
-This is how it will show up for file that we auto list in the library documentation:
+This is how it will show up for files that we auto-list in the library
+documentation:
 
 
 .. automodule:: theano.misc.doubleop

theano/misc/doubleop.py

@@ -8,7 +8,7 @@ class DoubleOp(theano.Op):
 
     :param x: input tensor.
 
-    :return: a tensor of the shape shape and dtype as the input with all
+    :return: a tensor of the same shape and dtype as the input with all
         values doubled.
 
     :note:
@@ -46,8 +46,8 @@ class DoubleOp(theano.Op):
 
     def R_op(self, inputs, eval_points):
         # R_op can receive None as eval_points.
-        # That mean there is no diferientiable path through that input
-        # If this imply that you cannot compute some outputs,
+        # That means there is no differentiable path through that input.
+        # If this implies that you cannot compute some outputs,
         # return None for those.
         if eval_points[0] is None:
             return eval_points