Fixed minor typos

theano/gof/graph.py

@@ -204,10 +204,10 @@ class Variable(utils.object2):
 
     - `Variable` (this base type) is typically the output of a symbolic computation,
     
-    - `Value` (a subclass) adds a default :literal:`value`, and requires that owner == None
+    - `Value` (a subclass) adds a default :literal:`value`, and requires that owner is None
 
-    - `Constant` (a subclass) which adds a default and un-replacable :literal:`value`, and
-      requires that owner == None
+    - `Constant` (a subclass) which adds a default and un-replaceable :literal:`value`, and
+      requires that owner is None
 
     A Variable which is the output of a symbolic computation will have an owner != None.
 

theano/gof/type.py

@@ -315,7 +315,7 @@ class Type(object2, PureType, CLinkerType):
     Type instance defines the kind of value which might end up in that variable when executing
     a `Function`.  In this sense, theano is like a strongly-typed language because the types
     are included in the graph before the values.  In our example above, b is a Variable which is
-    guaranteed to corresond to a numpy.ndarray of rank 1 when we try to do some computations
+    guaranteed to correspond to a numpy.ndarray of rank 1 when we try to do some computations
     with it.
 
     Many `Op` instances will raise an exception if they are applied to inputs with incorrect