Hello anyone,
I'm having a little difficulty understanding the solution to ex 3.3.1(e) the last wff, specifically how to quantifiers interact.
why is the order not interchangeable? I believe this hinges on the following question. Why can I not use an assignment v" that differs from v' at most on x2 where v' differs from v at most on x1 (v being the arbitrary assignment in which context we're trying to satisfy alpha)? i.e., in the solution, why is u said to be like v and not v'?
clearly there is a reason or the quantifiers would be interchangeable - I just can't see it.
Please help,
-Jason.