Neat Post Related to Formal Systems

Terence Tao is a brilliant mathematician whom I follow.  He posts about a lot of very interesting mathematical topics.  I found this neat post related to formals systems.  The beginning of the article should hopefully be at least somewhat familiar based on what I have discussed, but it does get heavy pretty quickly.  Nevertheless, check it out and enjoy!

Definable subsets over (nonstandard) finite fields, and almost quantifier elimination