2 files changed, 19 insertions, 9 deletions
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 2f6013e..baa6eaa 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1544,11 +1544,11 @@ Super Binding
    ``A.__dict__['m'].__get__(obj, A)``.
 
 For instance bindings, the precedence of descriptor invocation depends on the
-which descriptor methods are defined.  Data descriptors define both
-:meth:`__get__` and :meth:`__set__`.  Non-data descriptors have just the
+which descriptor methods are defined.  Normally, data descriptors define both
+:meth:`__get__` and :meth:`__set__`, while non-data descriptors have just the
 :meth:`__get__` method.  Data descriptors always override a redefinition in an
 instance dictionary.  In contrast, non-data descriptors can be overridden by
-instances.
+instances. [#]_
 
 Python methods (including :func:`staticmethod` and :func:`classmethod`) are
 implemented as non-data descriptors.  Accordingly, instances can redefine and
@@ -1817,6 +1817,9 @@ objects.  Immutable sequences methods should at most only define
 
    .. deprecated:: 2.0
       Support slice objects as parameters to the :meth:`__getitem__` method.
+      (However, built-in types in CPython currently still implement
+      :meth:`__getslice__`.  Therefore, you have to override it in derived
+      classes when implementing slicing.)
 
    Called to implement evaluation of ``self[i:j]``. The returned object should be
    of the same type as *self*.  Note that missing *i* or *j* in the slice
@@ -2112,6 +2115,13 @@ For more information on context managers, see :ref:`typecontextmanager`.
 .. [#] This, and other statements, are only roughly true for instances of new-style
    classes.
 
+.. [#] A descriptor can define any combination of :meth:`__get__`,
+   :meth:`__set__` and :meth:`__delete__`.  If it does not define :meth:`__get__`,
+   then accessing the attribute even on an instance will return the descriptor
+   object itself.  If the descriptor defines :meth:`__set__` and/or
+   :meth:`__delete__`, it is a data descriptor; if it defines neither, it is a
+   non-data descriptor.
+
 .. [#] For operands of the same type, it is assumed that if the non-reflected method
    (such as :meth:`__add__`) fails the operation is not supported, which is why the
    reflected method is not called.
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
index 476c82d..ef71a80 100644
--- a/Doc/reference/expressions.rst
+++ b/Doc/reference/expressions.rst
@@ -741,7 +741,7 @@ less tightly than unary operators on its right.  The syntax is:
 
 Thus, in an unparenthesized sequence of power and unary operators, the operators
 are evaluated from right to left (this does not constrain the evaluation order
-for the operands).
+for the operands): ``-1**2`` results in ``-1``.
 
 The power operator has the same semantics as the built-in :func:`pow` function,
 when called with two arguments: it yields its left argument raised to the power
@@ -959,12 +959,12 @@ Comparisons can be chained arbitrarily, e.g., ``x < y <= z`` is equivalent to
 ``x < y and y <= z``, except that ``y`` is evaluated only once (but in both
 cases ``z`` is not evaluated at all when ``x < y`` is found to be false).
 
-Formally, if *a*, *b*, *c*, ..., *y*, *z* are expressions and *opa*, *opb*, ...,
-*opy* are comparison operators, then *a opa b opb c* ...*y opy z* is equivalent
-to *a opa b* :keyword:`and` *b opb c* :keyword:`and` ... *y opy z*, except that
-each expression is evaluated at most once.
+Formally, if *a*, *b*, *c*, ..., *y*, *z* are expressions and *op1*, *op2*, ...,
+*opN* are comparison operators, then ``a op1 b op2 c ... y opN z`` is equivalent
+to ``a op1 b and b op2 c and ... y opN z``, except that each expression is
+evaluated at most once.
 
-Note that *a opa b opb c* doesn't imply any kind of comparison between *a* and
+Note that ``a op1 b op2 c`` doesn't imply any kind of comparison between *a* and
 *c*, so that, e.g., ``x < y > z`` is perfectly legal (though perhaps not
 pretty).