A similar mechanism is needed by the \method{__contains__()} and
\method{remove()} methods which need to hash an element to check
for membership in a set. Those methods check an element for hashability
-and, if not, check for a \method{_as_Temporarily_Immutable()} method
+and, if not, check for a \method{_as_temporarily_immutable()} method
which returns the element wrapped by a class that provides temporary
methods for \method{__hash__()}, \method{__eq__()}, and \method{__ne__()}.
The alternate mechanism spares the need to build a separate copy of
the original mutable object.
-\class{Set} objects implement the \method{_as_Temporarily_Immutable()}
+\class{Set} objects implement the \method{_as_temporarily_immutable()}
method which returns the \class{Set} object wrapped by a new class
\class{_TemporarilyImmutableSet}.