#3793: fix markup.

diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 879349081d242e39502d3c60bd2df8b60b0fe1f8..56eccc2bab6860eba506532873881d92d6b8842c 100644 (file)
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1262,6 +1262,7 @@ Basic customization
    explicitly set to :const:`None`.
 
 .. method:: object.__bool__(self)
+
    .. index:: single: __len__() (mapping object method)
 
    Called to implement truth value testing, and the built-in operation ``bool()``;