Question

¬(¬P ∨ Q) (Premiss)

P ∧ ¬Q (goal)

proof?

Answer 1

distribute the - thru, what do we get?

Answer 2

or is this a table proof?

Answer 3

p q -q -p -puq -(-puq) pn-q
1 1 0 0 1 0
1 0 1 0 0 1
1 1 0 0 1 0
1 0 1 0 0 1
0 1 0 1 1 0
0 0 1 1 1 0
0 1 0 1 1 0
0 0 1 1 1 0

you can fill in the last column

Answer 4

and dbl chk that i did the other columns correctly, thats was a pain to type

Answer 5

I'm suppose to do this with fitch, I know it's correct I just don't know how to get from ¬(¬P ∨ Q) to P ∧ ¬Q

so my question is how do you do the fitch proof for this one of demorgan laws