fixed definition list markup (removed blank lines); removed whitespace

pep-3119.txt

@@ -509,7 +509,6 @@ The built-in type ``set`` derives from ``MutableSet``.  The built-in
 type ``frozenset`` derives from ``Set`` and ``Hashable``.
 
 ``Set``
-
     This is a sized, iterable container, i.e., a subclass of
     ``Sized``, ``Iterable`` and ``Container``.  Not every subclass of
     those three classes is a set though!  Sets have the additional
@@ -557,7 +556,6 @@ type ``frozenset`` derives from ``Set`` and ``Hashable``.
     aliases for ``__le__`` and ``__ge__``.
 
 ``MutableSet``
-
     This is a subclass of ``Set`` implementing additional operations
     to add and remove elements.  The supported methods have the
     semantics known from the ``set`` type in Python 2 (except for
@@ -614,7 +612,6 @@ mapping API.
 The built-in type ``dict`` derives from ``MutableMapping``.
 
 ``Mapping``
-
     A subclass of ``Container``, ``Iterable`` and ``Sized``.  The keys
     of a mapping naturally form a set.  The (key, value) pairs (which
     must be tuples) are also referred to as items.  The items also
@@ -688,7 +685,6 @@ The built-in ``list`` and ``bytes`` types derive from
 from ``Sequence`` and ``Hashable``.
 
 ``Sequence``
-
     A subclass of ``Iterable``, ``Sized``, ``Container``.  It
     defines a new abstract method ``__getitem__`` that has a somewhat
     complicated signature: when called with an integer, it returns an
@@ -705,7 +701,6 @@ from ``Sequence`` and ``Hashable``.
     ``index``, ``count``, ``__add__``, ``__mul__``.
 
 ``MutableSequence``
-
     A subclass of ``Sequence`` adding some standard mutating methods.
     Abstract mutating methods: ``__setitem__`` (for integer indices as
     well as slices), ``__delitem__`` (ditto), ``insert``, ``append``,