# Homework Help: Nested quantifiers

1. Oct 2, 2011

### kramer733

1. The problem statement, all variables and given/known data

Question 5.

http://cg.scs.carleton.ca/~michiel/1805/assignment1.pdf [Broken]

2. Relevant equations

3. The attempt at a solution

I arrived here:

Exist X, All Y (P(x,y) and NEGATION (Exist z: NEGATION Q(x,y,z))

I have no idea how you guys do the notation. If anybody would like to show me how to use notation here at physics forums, it'd be great. Tried googling it but failed.

Last edited by a moderator: May 5, 2017
2. Oct 2, 2011

### issacnewton

very good reference for latex notation is at

tobi.oetiker.ch/lshort/lshort.pdf

for the list of mathematical symbols go to page 72 in pdf. also on this forum , there is latex help thread which can help you.

in the problem, you are doing good, you have carried $\neg$ till that point, why
don't you carry it forward , inside the bracket

3. Oct 2, 2011

### kramer733

I'm not sure what happens when you negate something inside a bracket. It confused me.

4. Oct 2, 2011

### issacnewton

$$\neg(\exists z(\neg Q(x,y,z)))$$

$$\forall z \;\neg (\neg Q(x,y,z))$$

$$\forall z \;Q(x,y,z)$$