propositions and logic help
Hi
I am having trouble understanding some subjects in maths, and seem unable to find similar examples elsewhere. I do not want to cheat, nor do this without understanding how it works, so I am hoping that someone can give me some ideas to help me figure this one out alone.
The question is:
if P then Q
if not R then not Q
P or R
Therefore, R.
I need to create a truth table or "any other method that works" to show that this argument is valid.
It may be a big ask, but I would really appreciate it if no one writes an answer so much as perhaps put this into a sentence so I may better understand it. As an example:
P= Eat your vegetables
Q= You will get dessert
I am not sure how R fits into this proposition, any help greatly appreciated!!
Also how/where can I get software or fonts which allow me to type the proper symbols and create tables so I can do this on my PC? Thanks!