Had to stop here for tonight but wow You simplified everything my prof taught me in like 3+ hours up to this point How many weeks of class versus the 3 hours spent here is a huge difference for me I actually understand stuff now
Professor Brehm, you taught me this so eloquently compared to my professor. My professor zoomed through the laws, zoomed through the process of the two column proof, and jumped straight into predicates. THANK YOU!
This semester I am having Linear Algebra and Discrete Structure Blessing for me to have both courses playlists from your channel. You are making these courses easy for me. Appreciate your efforts
I'm currently in a discrete structures class for y graduate degree and your videos saved my life. Thank you for your breakdown and for making the material enjoyable in a way rather than feeling like banging my head against a wall lmao.
Despite the fact I'm watching these videos for 8 hours straight, I'm still not bored. Finally I feel like I can actually solve these problems! thank you again.
Can someone expand the steps she took when she combined the commutative and associative laws at 10:30? As I understand it: (¬p ∨ ¬q) ∨ (p ∨ q) ≡ (p ∨ q) ∨ (¬p ∨ ¬q) - because communicative law This seems clear to me. But how do we get from this to swapping around the propositions contained within the ( )s on either side of the center ∨ to : ≡ (p ∨ ¬p) ∨ (q ∨ ¬q) via the associative law (p ∨ q) ∨ r ≡ p ∨ (q ∨ r) ? Where is the r in this case above?
Ya something that you must know from elementary math, theres alot of videos on associative methods online and youtube tho, suggest you watch those and come back. good luck!
I'm a bit late but my understanding on this works as follows: Think of disjunction as an addition operator in mathematics. In this scenario we are working with (p + q) + (-p + -q). This equation would be mathematically equivalent to (p + -p) + (q + -q). In mathematics, we can just rearrange this equation as needed as it won't affect the result. The same thing can be done with any disjunction similar to this AS LONG AS there is no other 'operator' involved within our proposition.
Hi professor, May I ask, essentially you would have to memorize the Different laws in order to do these question and everything would become easier? I am currently a international students studying in a uni with a professor whos english isnt great, so your videos have helped me understand so much better.
I'm having a hard time understanding how you chose the Law at timestamp 7:58. I've watched this like 8 times now lol Update: I just realized I was thinking of the variables in the Law as single variables, not compound propositions....
Could we have gone from (not p or not q) or (p or q) to not(p or q) or (p or q) and then to truth since p or not p is t? Sorry for not using the math symbols I don’t know how to do them on my phone. Thank you in advance and thank you professor for helping me with your series!
I think either is applicable, she misspeaks in the video saying T v p = p by domination law but I'm pretty sure she meant T v p = T by domination law, and idempotent law would theoretically work as well. However, I'm just a student as well so don't take my word for it.
I'm a little confused, doesn't DeMorgans law change the sign for "or" to "and" and "and to "or. So wouldn't the line say, (negate negate p OR negate q, instead of AND)
Learning propositional logic in class? 4 weeks. Learning propositional logic on youtube? An over caffeinated evening that became an all-nighter
😂😂😂😂😂
Had to stop here for tonight but wow
You simplified everything my prof taught me in like 3+ hours up to this point
How many weeks of class versus the 3 hours spent here is a huge difference for me
I actually understand stuff now
Literally in the same boat.
Seriously.. She is freaking amazing!!!
U actually just summarize what have u done try to understand in class, and u get better understanding at the second lecture
Professor Brehm, you taught me this so eloquently compared to my professor. My professor zoomed through the laws, zoomed through the process of the two column proof, and jumped straight into predicates. THANK YOU!
This semester I am having Linear Algebra and Discrete Structure Blessing for me to have both courses playlists from your channel. You are making these courses easy for me.
Appreciate your efforts
I'm currently in a discrete structures class for y graduate degree and your videos saved my life. Thank you for your breakdown and for making the material enjoyable in a way rather than feeling like banging my head against a wall lmao.
Despite the fact I'm watching these videos for 8 hours straight, I'm still not bored. Finally I feel like I can actually solve these problems! thank you again.
I'm so lucky I found you. You make everything elegantly smooooooth!
13:13 Shouldn't that be Demorgans 2nd Law since it was negation distrubitng a dijunction
thats what i thought too
exactly
Many thanks Professor Brehm for making your videos available. I am enjoying my logic class because of these videos.
13:19 why it is 1st de morgan rule, cuz we used V , isnt it second rule?
Kimberly Brehm, You are a lifesaver! Thank you!
you saved my life for tomorrow's final !!! THANK YOU SO MUCH PROF.B
9:26 wouldn't it be the 2nd De Morgan law in this one? Thanks for your videos, they are amazing!
Likely! I'm not great with details. I usually just say DeMorgans law 😜
thanks for the breakdown, Prof. B but I got to repeat this again for a better and clearer understanding.
Can someone expand the steps she took when she combined the commutative and associative laws at 10:30? As I understand it:
(¬p ∨ ¬q) ∨ (p ∨ q)
≡ (p ∨ q) ∨ (¬p ∨ ¬q) - because communicative law
This seems clear to me. But how do we get from this to swapping around the propositions contained within the ( )s on either side of the center ∨ to :
≡ (p ∨ ¬p) ∨ (q ∨ ¬q)
via the associative law (p ∨ q) ∨ r ≡ p ∨ (q ∨ r) ?
Where is the r in this case above?
Same stuck in a similar situation. Do let me know if you found out how to do it.
yup same question!
I have to come to realize that it's just something you gotta know. Its super dumb
Ya something that you must know from elementary math, theres alot of videos on associative methods online and youtube tho, suggest you watch those and come back. good luck!
I'm a bit late but my understanding on this works as follows:
Think of disjunction as an addition operator in mathematics. In this scenario we are working with (p + q) + (-p + -q). This equation would be mathematically equivalent to (p + -p) + (q + -q). In mathematics, we can just rearrange this equation as needed as it won't affect the result. The same thing can be done with any disjunction similar to this AS LONG AS there is no other 'operator' involved within our proposition.
12:10 sry but wouldn't it be 1st negation law not 2nd and isn't the domination law p v T = T? Otherwise, great video
Could someone please explain how the first step happened at 8:48?
love you teacher from Pakistan,It helped alot thank you.
Hi, I don't understand 10:30 with the commutative and associative law
need and help now
13:19 2nd DeMorgan law?
Hi Prof, Thank you for the great series
Should we be memorising the laws?
I don't make my students memorize them. I just suggesting getting to know them but having a "cheat sheet" in front of you with options you can use.
i don't understand how in minute 7:46 you went from P and Q too P implies Q
Hi professor, May I ask, essentially you would have to memorize the Different laws in order to do these question and everything would become easier?
I am currently a international students studying in a uni with a professor whos english isnt great, so your videos have helped me understand so much better.
13:15
- NOT NOT!
- Who's there?
- DeMorgan
- The who...?
- The true/false guy
- oh okay
DOOR = FALSE
at the time, 06:34, your lecture is excellent
I'm having a hard time understanding how you chose the Law at timestamp 7:58. I've watched this like 8 times now lol
Update: I just realized I was thinking of the variables in the Law as single variables, not compound propositions....
How do you know if it is 1st or 2nd DeMorgan's law? I thought the last one would be 2nd...
I was about to comment, that I think its the second Law as well.
It should be, and I guess that also answers your question... you don't know.
want to know too :')
First Law: ¬(P∧Q) is logically equivalent to ¬P∨¬Q.
Second Law: ¬(P∨Q) is logically equivalent to ¬P∧¬Q.
Could we have gone from (not p or not q) or (p or q) to not(p or q) or (p or q) and then to truth since p or not p is t?
Sorry for not using the math symbols I don’t know how to do them on my phone.
Thank you in advance and thank you professor for helping me with your series!
Isn’t T v T = T is by using idempotent law?
yeah same question
I think either is applicable, she misspeaks in the video saying T v p = p by domination law but I'm pretty sure she meant T v p = T by domination law, and idempotent law would theoretically work as well. However, I'm just a student as well so don't take my word for it.
Can someone explain what she means by "first or second law"? im taking notes of this, but i dont see where the first or second law is implied?
In the video playlist, I take you through the laws and explain each. Please watch the 1.3.1 and 1.3.2
I'm a little confused, doesn't DeMorgans law change the sign for "or" to "and" and "and to "or. So wouldn't the line say, (negate negate p OR negate q, instead of AND)
~(pvq)=~q^p solution is: ~p(~p^~q) [de-morgans law] ; ~q^p [commutative law]
Gonna need some practice to understand this. First video where I'm like what is going on. HAHAHA
thank you
You're welcome!
Done
why can't professors be like TH-cam tutors
Does anyone know where can i practice some examples
These negations look like the number 7 and its confusing me more!! Lol
how im going to remember that much laws and which ones are important. i hate these type of questions
I get it. But you don’t have to memorize them!
You made a mistake. P OR T is logically equivalent to T. P AND T is logically equivalent to P
3:51 🧐🤯😭🤔
Fine, now I'm using algebra property to understand this better and yes i am understand it now, thanks professor Kimberly
Seriously!?
The practice was obvious
At least give us something to think about!
Um your textbook examples??
@Kashif Khan No, the practice in the end of the video.
@Hassan Kalantari I meant use the examples in your textbook if you want a challange.
@@KashifKhan-ik7nn which textbook?
😑@@HeisenbergHK