Lecture 2 - Propositional Logic (Contd.)

[thedeathofbirth500]

Thank you for a wonderful lecture.I am looking forwards to the next.Please make sure they all have subtitles .You are a very capable professor.

[moe777]

Thank you Dr.Kamala , You're The Best !

[lovelplants]

oh this si nice

[1extenderpro]

wow

[pancitSharon]

About the tourist asking for directions:

The liar will lie about being a liar...So it seems that your single question won't work...It's actually not a single question, but two questions being asked--

1) "Are you a liar?", and

2) "Should i take the left road?"

To each of them, the liar will lie.

[Har1H]

Among stmts made(w.r.t stmt 2 of each person), stmt of A and stmt of B are contradicting(A said B was talking to E, B said B was not talking to E), so one of them is T, and the other is F.So now you know that stmt 2 of C and D are false(2F stmts left). So D did not commit the murder and Men did not commit the murder. Since A and C are men, and since D did not commit the murder, the murderer is B(The only woman left). Hope this helped :)

[Har1H]

@simplymusicism:1st thing is that each person has stated 2 statements, as shown on board(Stmt 1 and stmt 2).As per problem stmt, there are 4 true stmts, and 4 false stmts, and there is only 1 murderer.Since every person's 1st stmt is dat he/she is innocent,and since only 1 can murder E,3 people are telling the truth(w.r.t. stmt 1) and 1 is lying(Only 1 murderer is possible).So now among stmt 2(made by all 4),3 stmts are false and 1 is true[making a total of 4T and 4F stmts].chk next comment.

[simplymusicism]

in the murder mystery question, a can be true and b false and vice versa,

c and d's sec statement made false as it is.. i could not understand that . Can anyone explain piz

[isidbigi]

nice lecture but ur accent gets in the way most of the time

[rka420]

:)

[nipsboy123]

An excellent lecture! Thank you Dr

[ShantiOom]

I couldnt get the whole vedio, can anybody help??

[MrSeenibalaji]

THANKS A LOT MAM... VERY USEFUL ONE...

[sakthitvmalai]

MAM,you said that we should take ~A from [(~A v B ) v (~A v D)] and the result is

[~A v (B v D)]..... but my doubt is that will it violate distributive law..? please anyone help me..

[Drewtmulock]

@sakthitvmalai Hey man not sure if you got your question answered but here it goes: [(~A v B) v ( ~A v D ) ] Because we are just dealing with v the brackets dont mean much. So we can write [ ~A v B v ~A v D ] we can rearrange this to: [ ~A v ~A v B v D ] [ ~A v ~A ] can be simplified to just [ ~A ] using the Law of Idempotence this leaves us with [ ~A v (B v D ) ] again the brackets are more for show. Hope that helps : )

[sakthitvmalai]

@Drewtmulock thank you...now i understand.....



[faby2004]

Awesome Video!!! Thank you very much for your time to create it!

[faby2004]

Awesome video!

[chintanbiz]

Awesome, Thanks a lot to Dr. Kamala and IITs for this kind of help to the students of INDIA and world. I can't explain in words that how much help I got from this! I am very poor in Maths and this acts like my personal tutions without any fees!! Please never stop creating this kind of channels you and your teams means a lot for the students like me. THANK YOU VERY VERY MUCH....

[ThisSentenceIsFalse]

I see the comment box on YouTube is still acting up. Sorry for the repeats.

[ThisSentenceIsFalse]

Oh, I see where I went off the rails. I confused propositions with inference. Validity applies to arguments not propositions.

[ThisSentenceIsFalse]

Oh, I see where I went off the rails. I confused propositions with inference.  Validity applies to arguments not propositions.

[ThisSentenceIsFalse]

I saw in the last video how the contrapositive (if ~Q then ~P)was derived with truth tables, but I'm not at ease with it. For instance, if you are a male, then you have a penis--the contrapositive is if you don't have a penis, then you are not a male. Sounds good, but some males don't have penises--eunuchs for instance, they did, but now they don't. Of course, the truth or falsity of a proposition doesn't determine the validity of it's propositional form, so maybe I'm off the rails somewhere.

[sogasg]

Thank you :) super for the lectures I missed.

[shery738]

yes u can take discrete coz calculs is not pre-req for discrete

[meen2anend]

Can I take discrete math without having taken calculus???

[SchizoKnight12]

yes. and it is easier than calc. also, you might want to study logic before discrete math. it isn't required but it will save you alot of heartache. also make sure you devote proper time to logic and discrete math. failure to do so will lead to disappointment.

[mosgba]

what is the meaning this welcome song people haha. sounds good though :)

[lbdeyo]

What a pleasure to find such excellent lectures, so elegantly presented.

American viewers should, however, be advised of some pronunciation idioms. When Dr. Kamala seems to say, "Yay implies B. R. D." she's actually saying, "A implies B or D."

[IsThisNoGo]

Ok that's fine,sorted out the modus ponens and modus tollen, in a more sensible manner ,than I have been used to.I haven't come across the way they are represented, like this before,but it's logical.

Lets see how "predicates and quantifiers" go.

Thank you.

[aaron1976]

Thank you but please get different chalk lol Sqweek Sqweek

[mayaluvsmusic]

thanks Dr Kamala

[Shukria123]

Satnaam Waheguru

[plusindia]

This is wonderful e-learning experience for this non computer science academic professional

[CoffeeStudios]

Apologies, was a bit angry at the time.

[mathstudent1234]

Thank you Dr. Kamala! You are wonderful and I can't thank you enough. Wonderful lecture.

[ramkumarkoppu]

Thanks IITM :-)

[ouroboros98]

That's Dr Kamala to you

[CostaDelBarto]

That's professor Kamala to everyone, surely.

She gives a nice and methodical treatment.

[z11aalex]

Excelent! had the same feeling of Mrs Kamala`s prononciation, but now got used to it. Very understandable explication, Thank you Mrs Kamala!

[OliveiraBR22]

Very good video, Mrs Kamala knows very well to transmit her knowledge, in the beggining was hard to undestand her accent but now I can absorb what she teach even with eyes closed :D