fixed the docstring.

theano/scan_module/scan_opt.py

@@ -212,9 +212,8 @@ def remove_constants_and_unused_inputs_scan(node):
 # It should be possible to change it to a local opt.
 class PushOutNonSeqScan(gof.Optimizer):
     """
-    A global optimizer for pushing out the variables inside the scan that
-    are not used by the scan.
-
+    A global optimizer for pushing out the variables inside the scan that depend
+    only on non-sequences.
     """
 
     def __init__(self):
@@ -411,9 +410,8 @@ class PushOutNonSeqScan(gof.Optimizer):
 # It should be possible to change it to a local opt.
 class PushOutSeqScan(gof.Optimizer):
     """
-    A global optimizer for pushing out the input variables that are not being
-    used inside the scan and provided in the sequences.
-
+    A global optimizer for pushing out the variables inside the
+    scan that depend only on constants and sequences.
     """
 
     def __init__(self):
@@ -659,7 +657,6 @@ class PushOutScanOutput(gof.Optimizer):
     """
     This is an optimization that can push operations performed
     at the end of the inner graph of scan to outside of scan.
-
     """
 
     def __init__(self):