Typo fix.

Doc/lib/libstdtypes.tex

@@ -330,7 +330,7 @@ One method needs to be defined for container objects to provide
 iteration support:
 
 \begin{methoddesc}[container]{__iter__}{}
-  Return an interator object.  The object is required to support the
+  Return an iterator object.  The object is required to support the
   iterator protocol described below.  If a container supports
   different types of iteration, additional methods can be provided to
   specifically request iterators for those iteration types.  (An