Propositional Logic − Logical Equivalences
ฝัง
- เผยแพร่เมื่อ 7 ก.พ. 2025
- Discrete Mathematics: Propositional Logic − Logical Equivalences
Topics discussed:
1) Logical Equivalence definition and example.
2) Most common and famous logical equivalences.
3) Logical equivalences involving conditional statements.
4) Logical equivalences involving biconditional statements.
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What's more important than proving this thing is you gave a proper explanation of what a logical equivalent are🤦♂️ In my University the professor was just like read it this are formulas🤣
you know, my mind is like yeah okay i get it but what again? hahahaha
fr
Hi
ifyyyyy🤐
Same
@@maazfaridi5946 hey are u studying in country where speaking native english
I have a test today and this confirmed I will be failing that exam.
Same
😂
Did u
@@Salamanca-joro i got 23/30 DSGT IS EASY THOUGH🤣🤣
@@drinetorshorts I am taking this subject this semester and my first lesson was this week about this topic , idk this whole thing seems easy to me I hope it keeps being this way so i can get A 😂
7:40 this explanation is exactly what I was looking for! Up until now everything had made sense to me except this part, and our teachers just told us to "remember it and you're good" instead of explaining it, now that you've proven it and explained it I got clarity. THANK YOU SO MUCH!
Me too
now this is the kind of stuff which is complicated and simple at the same time due to this channel !!!!!
You are amazing! Thank you for making this so clear and easy to understand!
Better explanation then the one my professor gave or what's in the trash book they made us buy
Same situation bro
how much bro
can anyone explain that in proving the absorption law, when he took p as common why did he change the signs.. like ^ to or and or to ^ .. time 5:36
@@hariszaib2728 As mentioned here p^1 =p, so the 4th step can be written as (p^1)\/(p^q). Then by taking p as common by distributive law, we get p^(1 \/q)
Loll, sammee
for absorption law (a), another way to think is that either p or p and q needs to be true for the expression to be true. Hence if p is false, the expression has to be false and if p is true the expression has to be true. So its equivalent to p. Similar logic holds for (b)
P this p that imma drop this major brah
I just want to say THANK YOU!! You`re doing a great job on your videos, keep up the good work!
Really helpful and yes I have done my home work ☺️😁
Thank you sir 😊
Negation(p implies q) equivalence p and negation of q
Using (p implies q) equivalence to negation of p or q
Negation ( negation of p or q) equivalence p and negation of q
Then use de Morgan rule
P and negation of q is equivalence to p and negation of q
Thanks yaaa
Did you know that you are an amazing teacher? Thank you!
Wow have had a great understanding of everything.Thanks for the good work.
Amazing way of teaching...
شكرا و جزاك الله خيرا
you are so much better than my lecturer
thanks for existing
Your voice is like Rajesh Koothrappali’s. Thank you for video
In big bang theory right???
@ right
احسنت الشرح جدا بسيط وواضح ❤️
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❤
The answer for home work problem in Biconditonal
Note: Symbols used ('^' and),('√' or),('->' conditional) and ('' Biconditonal)
Q] ~(pq) = p~q
Here is the solution
~(pq)= ~{(p->q) ^ (q->p)}
Using demorgans law in RHS
~(p->q) √ ~(q->p)
Using 5th stmt in conditional equivalence
(p^~q) √ (q^~p)
Let s=p , r=~q
So, (s^r) √ (~s^~r)
Using 3rd stmt in Biconditonal equivalence
s r
This is equal to "p~q"
I think im correct
Thank you
Thanks man
@@smammahdi teko kaise pta 🧐
Can you tell me how to prove that first biconditional statement
@@royalcanon7433 Hey buddy i think you missed this video on bi- conditional property in the playlist, here is the link of video below
th-cam.com/video/ehKd3KmIRSw/w-d-xo.html
Any way lemme help you out with simple example let us consider this example
P: is a polygon with 4 equal sides
Q: is a square
So, if P is true and Q is true then the proposition is true
If P is true and Q is false or P is false and Q is true then the proposition is false
This seems a tricky one if P is false (not a polygon) and Q is false(not a square)
This makes sense bcoz its not a square since its not a polygon
I hope it helps ,Good luck 🎉
Is (p^~q) = (~q^p) ?
10:24
Not(p->q) =p^not(q)
=not(not(q) -> not(p))
=not(p->q)
where p=not(q) and q=not(p)
Therefore, Hence Proved!!!
In last question ~(pq)=p~q proved and it is also = ~pq
Just check anybody please
This is the hardest part of logic
Great video! I loved how you went in depth and proofed all logical equivalences!
Your teaching is so nice or understanding thank
Last question.
NOT (p biconditional q) is equivalent to (p biconditional NOT q)
NOT (p biconditional q)
= NOT ((NOT p AND NOT q ) OR (p AND q)) [Biconditional into implication into combination of NOT, AND, OR]
= (NOT p OR NOT q) AND (p OR q) [DeMorgan's Law]
= (NOT p OR NOT q) AND (NOT(NOT q) OR p) [Double Negation Law]
= (p implies NOT q) AND ( NOT q implies p) [Implication]
= p biconditional NOT q [Biconditional]
Hey bro
Can you text me on instagram pls
This is my acc
ha_a_21.11
can you explain this line = NOT ((NOT p AND NOT q ) OR (p AND q)) [Biconditional into implication into combination of NOT, AND, OR]
@@JonesSmiraj5626 A B is logically equivalent to (A -> B) AND (B -> A) which is logically equivalent to (NOT A AND NOT B) OR ( A AND B)
@@subhradipsaha9518 thank you for that but A-> B is logically equivalent to NOT A OR B.........
from where u got the (NOT(NOT q) OR p)?
Sir, please post the solution to homework problems in the description box so that we can verify or modify our solution
what is the link of the homework?
@@abe22er it is given the end of video
The solution of first h.w. is :¬(p_>q). Because we took ¬ out and replaced ^ with _>, So we equivalent the RHS and the LHS.
Very simple yet effective explanation. Thanks a lot!
At 5:36 I'm confused as to what it means "taking p as a common". I see that p is converted to 1 and I'm confused as to how that happened
Exactly my thought. The 4th step and the question is exactly same. How does this work?
I also have this confusion @nesoacademy please help!
p is present on both the sides of the or (v) operator: p v (p ^ q), so the same expression can be written as p multiplied/and (^) with the entire expression by taking out the p in both the operands and replacing it with 1 (to create the same effect after the multiplication with p).
Thank you Neso Academy, detailed explanation, but I have a very confusing question and quiet difficult to break it down, don't know if you can help out
lol so you're just whining or what
that's not how math works
@@yasserfathelbab1534 chill out man
@@raannnggggaaaaa Two years now and not a soul knows what the question is.....
@@yasserfathelbab1534 still now I didn't get answers of that questions from homework.
For the homework #5 I got, -(p -> q) == -(-p v q) {Conditional Law} == - -p^-q {DeMorgans Law} == p^-q {Double Negation Law}
Please let me know if this is right or how I did!
This is correct
great video!
I solved the HW and understood why there is no posting of it. haha :D To give you a hint, it is pretty lengthy. yo. My humble respects to the teacher.
Can u plz give me the solution
Would be nice if you put the correct answer to your question in description so i can confirm if my answer is correct or not.
Thanks for your best tutorials!!🤩
for the 5th : we have ¬( p -> q ) = p ^ ¬ q ; ................1
we know from the 1st proof that : ( p -> q ) = ¬ p ν q , therefore substituting this same value to : [ ¬( p -> q ) ]
we get : ¬( ¬ p v q ) = p ^ ¬ q ; ..............................2
Now by DeMorgan's Law : ¬( p v q ) = ¬ p ^ ¬ q
by applying demorgan's law and solving the 2nd equation we'll get : ( p ^ ¬ q ) = ( p ^ ¬ q )
hence therefore, LHS = RHS
Thank you so much ❣❣💯💯❣❣
I am from Algeria and I enjoy to see your vedios🥰🥰🥰
Hii, wr is Algeria..
omg its so complicated
Padhai wadhai karo ias wias bano ❤
Thank you i got it ...
Thank you Neso Academy
I don't quite get how you solve the equivalences of biconditionals differently. The solution to number two is different from number three. In number two, you negated both p and q, but in number three you negated only p for the same conditions.
Dude i owe u !! ❤ thanks
Subscribed !
Thanks sir.. Really helpfull 👍 👍
5:38 What does "Taking P as common" mean?
Do you know now?explain me
Thank you so much 💕💕💕💕💕💕💕
I am from India and I enjoy to see your vedios.
Thank you so much for explaing the laws which is more helpful in solving the problem thanks a lot
If only the test is this easy
very simple explain
You just saved me. Thank you for this video
5:37 😂 4th line is same place where you started to prove formula . By the way I like Boolean notation more , it's easier because we are familiar with + , .
love your videos man, really helpful, thank you veru much!!!
Thank you! This helped me a lot!
LIFE SAVER!!!!
For the homework #4 involving bi-conditional statements like the following: "-(p q) = p -q " For this one I broke it like this "(-p -> -q) or (-q -> -p) = (p-> -q) (-q-> p) . Based on the Double negate law, " (-p-> -q) or (-q-> -p) is True as well as (p->-q) (-q-> p) which are True because no matter what if p is false it doesn't matter if q is False or True, p->q will always be TRUE. This is why they are equivalent. Any one want to give suggestions if I'm the right track here?
i think you r r18
can anyone explain that in proving the absorption law, when he took p as common why did he change the signs.. like ^ to or and or to ^ .. time 5:36
@@hariszaib2728 it wasn't p as common it was p^p=p
How can I master these laws and how hey are applied
Sir can you please answer the explanation of question 5th (homework) in biconditionals.??
Hi sa akong mga classmate ara sa Discrete HAHAHAHAHA. Tan aw lang sa ta youtube ani kay wa ta kasabot.
halooo clasmit IT ko g2 sa discrete ni arellano 1st year oks hhahha
haha
patulong, san niya galing yung ~(~q v~p)? 9:45
thank you very much dude, I am just learning this for myself as I have graduated from school long time ago. but bruh! wat in the multiverse is this shoot! Aliens laugh at us with all these nonsensical convention we brought. I am learning and laughing at this!
is it required to memorize all this logical equivalences..?
Before this im still confusing about law of logical equivalences. Watching this before exam
am i the only one that does hear and see what he says/show's perfectly but my brain just wont comprehend it :(
Thanks, this cleared things up for me
Hey which level(9/10/11grand) subject is this
Awesome man
Thank you sir🙌🏻
Are we prove them with the help of truth table??
Thank you Indian Guy(i dunno what's your race is) but it really help me a lot since I have midterm exam today
Made me realize how simple it is.
I'm watching this for 7th time .. but still can't 💔
I get all of this but do i have to memorize these laws
Excellent !! Excellent!! nothing else to say.
You please do some video lectures ( even paid ) on model checking buchi automata etc.,
Explanation is well done 👍 sir
Superbbbb sir...
For the Homework (5): is -(p->q) = p and -q are equivalent because if you break it down like following:" -p implies - q" makes that statement True while "p and -q" makes the statement TRUE. Because they both have true values makes the statement true and equivalent. Is that why? Can someone explain to me or check if I'm the right track? Thank you in advance!
You have applied theoretical knowledge of the understanding of the equivalence, I guess it's correct!!
The more simpler way that I used is to use De Morgan's laws that sir initially explained to prove it and it becomes just a three liner proof!
Hoping that helped...
Welcome in advance
now you've said that "-p" implies "-q", and that's true so from there we can agree that "q" implies "p" which is also correct. but the problem is that we can't return back and say that "-q" and "p" are equivalent, the equivalent here is p and "q'' .
the homework itself for me is not logical WHY, coze we have -(pq) which is also (pq) but not (p-q). let's make things even more simple, we have "q" and "p", both are equivalent then we say that "p" and "-q" are also equivalent which make no sense like if "a" is "a" then we say "a" is "-a which stands here for another alphabet different from a" and that's not so true.
Thank you so much my dude
In which class is this subject covered?
@@venusunbagcg6171 betch cse in sem 4
pls check if i am correct with 5th homework task:
NOT(p=>q) p and NOTq
We can transform it as following: (we can do a double negation of both sides)
NOT(NOT(p=>q)) NOT(p and NOTq)
(p => q) (NOTp or q) (right side is the same as 1st conditional statement)
please correct me!
Thanks sir alot😀
Better than in college. Thank you.
Thank you so much
can you solve to me (p^q)/bi implies p and p=>q/implies in logical equivalence if p,q and r use a truth table please ?
is there any sites where we can practice these questions
I only understand the double negation law 😅
9:45
my dummy self would have put a double negation on the p. But I guess it is commutive(you can switch the p's and q's)
Would it be wrong to do that? Is it only logically equivalent if you give it no one that isn't already negated?
where did he get the ~(~q v ~p)?
can anyone explain that in proving the absorption law, when he took p as common why did he change the signs.. like ^ to or and or to ^ .. time 5:36
In 4th line -
p v (p^q) = (p^1) v (p^q)
= p^(1 v q) [ taking p common ]
Do it like this - P + P.Q [Just like boolean algebra from Digital logic]. Now, i can easily take common and solve. Right ?
How to prove the last ones 12:15
Outstanding
Sir, prove for me -(PvQ)^-p)=>Q
Thank you....
Thanks
Thank you!
Sir please upload signals & systems lecture
So the three vertical lines is "="
great explanation
Thank you sir all of my doubts finally got cleared
Can I ask if a distributive can be two statements only, something like
(p v q) ^ ¬p ≡ ¬((p v q) →p)?
Thank you very much sir.... clearly understood...... Excellent explanation.....
HELPFUL VDO
Can I solve this using truth table straightly?
Yoo thanks 👏
Well That was Cool
complicated enough