- #1
LauraSuh
- 4
- 0
Hello smart people!
I was having some troubles proving this derived rule using Natural deduction:
¬(∃y.Q(y) ∧ T(y))
------------------------
∀x.Q(x) → ¬ T(x)
I got stuck in the very first line, because of the "NOT". I can't do anything if I don't take it out of there...
I know that ¬(a ∧ b) = ¬a ∨ ¬b, but I don't know how to prove that as well...
If I could only get past this very first step I'd be able to finish it, but I've been trying for hours and I can't get around it.
Please help!
I was having some troubles proving this derived rule using Natural deduction:
¬(∃y.Q(y) ∧ T(y))
------------------------
∀x.Q(x) → ¬ T(x)
I got stuck in the very first line, because of the "NOT". I can't do anything if I don't take it out of there...
I know that ¬(a ∧ b) = ¬a ∨ ¬b, but I don't know how to prove that as well...
If I could only get past this very first step I'd be able to finish it, but I've been trying for hours and I can't get around it.
Please help!