Professor Thorsby explains how to build propositional proofs using the rules of implication (Constructive Dilemma, Simplification, Addition, and Conjunction).
You are a lifesaver. It's nice to see other people from 4, 5, or 6 years ago who also valued your help. I'm sure someone will read this in the future and also think the same thing lol.
Thank you for everything! This is an immensely helpful tool for understanding logic. I cannot thank you enough for helping all of us who are struggling!
You are a wonderful prof!!! Thank you so much for helping us. I think every logic prof should have to watch your videos to see how to teach. I always understand the material better when you present it. Thank you for saving our grades!! :)
You should do note taking software reviews. I haven't seen you use the same software twice. All joking aside, you managed to clear up the mess of an attempt my professor made at explaining this topic. Thanks for saving my GPA.
For the constructive dilemna, CD, can we at first make two simplification of the first hypothsesis so that we get p implies q and r implies s and them bring them as hypothesis?
Regarding the rule of addition, do you have to have a single term isolated to add? For instance, if I had A v B, could I then use the rule of addition to say (A v B) v C?
so i just can add any value to B? for example my goal is ~P or R, i have ~Q or R on line 6, then i do my magic again and get ~P, can i just take R from line 6 and add it to ~P and that way get the answer i need?