[FOM] Sorry, yet another historical question

[T.Forster at dpmms.cam.ac.uk]

In fact, two!

(i) Is there a decent historical article anywhere outlining the emergence 
of the idea of the *Abstract data Type* (aka ADT)? I would very much like 
to read one if there is! I have recently been having a conversation with a 
philosopher of mathematics who loses sleep over what he calls the 
*C{\ae}sar Problem* (If you don't know what it is, don't ask!) and it 
prompted the reflection that if he were introduced to the idea of an ADT he 
might be a happier and more productive man.

Of course, if there is no such article yet, it would be a good project to 
write one.  Accordingly any historical tips and pointers into the literature
will be gratefully received.

(ii) The omitting types theorem for (classical) propositional logic. I 
published an article the other day which used it, and i airily said that i 
wouldn't supply a proof co's it's standard in the literature. On checking 
said literature, i find myself unable to locate any proof or even any 
allusion to one! Does anyone on this list know who first proved it and 
where?

Those of you who teach propositional logic might find - as i have found - 
that the extended omitting types theorem for propositional logic makes a 
good exercise for the stronger students.

 Pointers appreciated

      tf