I don't know if this the place to post this question, but I guess I can always try.
My questions are regarding Logic.
1) I'm trying to prove 'proof by cases' - X v Y, X -> Z, Y -> Z |- Z
I'm trying to prove it using the natural rules, but am having problems!
2) Using proof by cases, I want to prove the implication rule: A -> B |- ¬A v B
Either that, or by using natural rules.
This is really starting to annoy me - as I have spent a long time working on this!
Any help / advice would be helpful!