Remove the restriction on a mapping's .update() method.
diff --git a/Doc/lib/libstdtypes.tex b/Doc/lib/libstdtypes.tex
index bcedf71..f606d78 100644
--- a/Doc/lib/libstdtypes.tex
+++ b/Doc/lib/libstdtypes.tex
@@ -933,19 +933,19 @@
\lineiii{\var{a}.keys()}{a copy of \var{a}'s list of keys}{(3)}
\lineiii{\var{a}.update(\var{b})}
{\code{for k in \var{b}.keys(): \var{a}[k] = \var{b}[k]}}
- {(4)}
+ {}
\lineiii{\var{a}.values()}{a copy of \var{a}'s list of values}{(3)}
\lineiii{\var{a}.get(\var{k}\optional{, \var{x}})}
{\code{\var{a}[\var{k}]} if \code{\var{k} in \var{a}},
else \var{x}}
- {(5)}
+ {(4)}
\lineiii{\var{a}.setdefault(\var{k}\optional{, \var{x}})}
{\code{\var{a}[\var{k}]} if \code{\var{k} in \var{a}},
else \var{x} (also setting it)}
- {(6)}
+ {(5)}
\lineiii{\var{a}.popitem()}
{remove and return an arbitrary (\var{key}, \var{value}) pair}
- {(7)}
+ {(6)}
\lineiii{\var{a}.iteritems()}
{return an iterator over (\var{key}, \var{value}) pairs}
{(2)}
@@ -972,17 +972,15 @@
\var{key})} pairs using \function{zip()}: \samp{pairs =
zip(\var{a}.values(), \var{a}.keys())}.
-\item[(4)] \var{b} must be of the same type as \var{a}.
-
-\item[(5)] Never raises an exception if \var{k} is not in the map,
+\item[(4)] Never raises an exception if \var{k} is not in the map,
instead it returns \var{x}. \var{x} is optional; when \var{x} is not
provided and \var{k} is not in the map, \code{None} is returned.
-\item[(6)] \function{setdefault()} is like \function{get()}, except
+\item[(5)] \function{setdefault()} is like \function{get()}, except
that if \var{k} is missing, \var{x} is both returned and inserted into
the dictionary as the value of \var{k}.
-\item[(7)] \function{popitem()} is useful to destructively iterate
+\item[(6)] \function{popitem()} is useful to destructively iterate
over a dictionary, as often used in set algorithms.
\end{description}