Let's say we had a dictionary Axy = x agrees with y; b = Bob. Consider the following:
- $\neg \forall x Axb$
- $\forall x \neg Axb$
They both seem to translate to "There is no one that agrees with Bob". Would there any difference between the placement of the negation?
The second statement $\forall x\neg Axb$ means "for every person, it is not true that this person agrees with Bob", in other words,
$\forall xAxb$ means "everybody agrees with Bob", so the first statement $\neg\forall xAxb$ means "it is not true that everybody agrees with Bob", that is,
These statements are not the same.