Re: Using the RM for ADTs

David BL wrote:

[...]

>I would like to confirm my understanding here: FOL restricts
>quantification to be over elements in the domain of discourse, whereas
>SOL also allows for quantification over sets. In particular testing
>for existence of an isomorphism is quantification over a set because a
>function is basically a set of pairs.

I'm not aware that SQL allows anything like this. Can you give me an example?

>On a somewhat unrelated note, Ron Fagin has been mention occasionally
>on cdt. He proved in his PhD thesis that existential second order
>logic corresponds to the computational complexity class NP. I've just
>come across this:
>
>http://www.almaden.ibm.com/cs/people/fagin/genspec.pdf

I never read this, it looks interesting.

-- 
Reinier