Fix typo (GH-21820)

diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
index 7028d240c59ebb428e19809d44ebc7ac77adcc10..5a10faa7bbd293b7506231bdfaa35c9dc84c3997 100644 (file)
--- a/Doc/library/stdtypes.rst
+++ b/Doc/library/stdtypes.rst
@@ -4205,7 +4205,7 @@ The constructors for both classes work the same:
 
 
    Note, the non-operator versions of :meth:`union`, :meth:`intersection`,
-   :meth:`difference`, and :meth:`symmetric_difference`, :meth:`issubset`, and
+   :meth:`difference`, :meth:`symmetric_difference`, :meth:`issubset`, and
    :meth:`issuperset` methods will accept any iterable as an argument.  In
    contrast, their operator based counterparts require their arguments to be
    sets.  This precludes error-prone constructions like ``set('abc') & 'cbs'``