Fix punctuation.
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index bb392fc..7579cc9 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -1047,8 +1047,8 @@
    but some features (such as :func:`len`) will raise :exc:`OverflowError`.
 
    .. versionchanged:: 3.2
-      Implement the Sequence ABC
-      Support slicing and negative indices
+      Implement the Sequence ABC.
+      Support slicing and negative indices.
       Test integers for membership in constant time instead of iterating
       through all items.