23.3
----

... and returned by either a pop (stack) or a front (queue)
                             ^^^
top?


calc.cpp
--------

Lack of return stmt. in main() intentional?


tele.cpp
--------
line 52, TelephoneDirectory::find_entry

should the line be

iterator p = database.find( name );

rather than

iterator p = database.begin();

Let me know, I changed it in the notes.


Chptr. Summary, item #2
-----------------------
... extended though the use ...
             ^^^^^^
through



