It would've been very helpful if some sort of glossary or even a Wikipedia link was provided before diving into the use of the notational characters such as those used in "∀x !P(x)".

Although this post covers an important topic, the first few sentences almost lost me completely, even though I learned what all those characters meant at one time.

And, as LessWrong is rather enamored with statistics, consider that by writing P(x,y), the readers have an exactly 50% chance of getting the opposite meaning unless they have very good recall. :)