Fix some issues found by Jacques Ducasse on the docs list.

Doc/library/sys.rst

@@ -127,13 +127,12 @@ always available.
 
    .. index:: object: traceback
 
-   If no exception is being handled anywhere on the stack, a tuple containing three
-   ``None`` values is returned.  Otherwise, the values returned are ``(type, value,
-   traceback)``.  Their meaning is: *type* gets the exception type of the exception
-   being handled (a class object); *value* gets the exception parameter (its
-   :dfn:`associated value` or the second argument to :keyword:`raise`, which is
-   always a class instance if the exception type is a class object); *traceback*
-   gets a traceback object (see the Reference Manual) which encapsulates the call
+   If no exception is being handled anywhere on the stack, a tuple containing
+   three ``None`` values is returned.  Otherwise, the values returned are
+   ``(type, value, traceback)``.  Their meaning is: *type* gets the type of the
+   exception being handled (a subclass of :exc:`BaseException`); *value* gets
+   the exception instance (an instance of the exception type); *traceback* gets
+   a traceback object (see the Reference Manual) which encapsulates the call
    stack at the point where the exception originally occurred.
 
    .. warning::
@@ -508,9 +507,7 @@ always available.
    more information.)
 
    The meaning of the variables is the same as that of the return values from
-   :func:`exc_info` above.  (Since there is only one interactive thread,
-   thread-safety is not a concern for these variables, unlike for ``exc_type``
-   etc.)
+   :func:`exc_info` above.
 
 
 .. data:: maxsize

Doc/reference/simple_stmts.rst

@@ -146,16 +146,12 @@ Assignment of an object to a single target is recursively defined as follows.
   * Otherwise: the name is bound to the object in the global namespace or the
     outer namespace determined by :keyword:`nonlocal`, respectively.
 
+  .. index:: single: destructor
+
   The name is rebound if it was already bound.  This may cause the reference
   count for the object previously bound to the name to reach zero, causing the
   object to be deallocated and its destructor (if it has one) to be called.
 
-  .. index:: single: destructor
-
-  The name is rebound if it was already bound.  This may cause the reference count
-  for the object previously bound to the name to reach zero, causing the object to
-  be deallocated and its destructor (if it has one) to be called.
-
 * If the target is a target list enclosed in parentheses or in square brackets:
   The object must be an iterable with the same number of items as there are
   targets in the target list, and its items are assigned, from left to right,