How to do Natural Deduction Proofs | Attic Philosophy

Natural Deduction might be the simplest way to do proofs in logic. But how does it work? Let's find out!

This is part of a series of videos introducing the basics of logic. If there’s topics you’d like covered, leave me a comment below!

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#logic #proof #naturaldeduction

[i-FaizanulHaq]

Literally didnt understand this for 5 weeks in uni, and just watching u for 10 mins was enough to complete my whole assignment....THANKYOU SO MUCH

[xavieryuchi]

Thanks for the video, combined with the Carnap textbook I am using for my philosophy class at college!

Hello from a freshman in California!

[mel.o.ayo-]

I’m approaching the topic of natural deduction proofs at the university. I didn’t know exactly how natural deduction works. But at the time when I came across your video of efforts to throw light on it, I kinda was starting to slowly but surely understand how it works. Thank you so so much. By the way, I subscribed your channel. 😊

[FelixGigler]

Wow I didn't expect to finally understand canceling in ND. You even used a different notation of ND than in my lecture (yours is much clearer).

[carteroxley]

Hey there. My teacher has an odd habit of throwing very challenging versions of things at us after teaching us the rules of things. How do you solve something that looks like this: Premise: A -> (E -> B) Conclusion: (A /\ E) ->B

[carvingbell]

Hello Professor, I am not that tech savvy and in this video, you recommend watching the video prior to this one. I noticed that your videos are not numbered. I can not find the video before this one. I did a search "how to proof natural deduction" and I ended up with this one as the starting. Thank you.

[LECityLECLEC]

This video is incredibly beautiful. Thank you for putting the time and effort to do the subject justice. Instantly made me a fan! God bless!

[govighankrish]

Hi great really helpful video on natural deduction, when will you release one with the natural rules as I'm struggling with it right now. Thanks.

[mohamedstudentbenabdelouah]

Sir ! first I want to thank you about your work, i have a question: what is the purpose of the logic course in an IT engineer student career, many thanks

[poklar]

Great video as always! Any chance you’d be willing to do one about sequent calculi?

[MathCuriousity]

Hi love your channel and may I ask a question:

If in set theory, I can create a relation which takes a set of elements which are propositions (like set a is a subset of set b) and map it to a set of elements containing “true” and “false”, then why is it said that set theory itself can’t make truth valuations?

I ask this because somebody told me recently that “set theory cannot make true valuations” Is this because I cannot do what I say above? Or because truth valuations happen via deductive systems and not by say first order set theory ?

[xavierjarvis]

You're an absolute bloody legend. Cheers from Australia!

[gonzajuarez]

Heyy really useful stuff. Just one question. Why are assumptions scoped? I mean, if the conclusion made in an inner scope reached to a conclusion that will be used in the outer scope, then might as well the assumption be usable in the outer scope. I'm not saying that "spilling" assumptions to the outer scope feels clean at all (feels like uncontrolled side-effects in programming), but just a thought.

[sajankumarkar]

I swear you are a fucking savior. Much love from India

[theMelMxshow]

Hi! I've always struggled with Natural deduction, vey helpful, for instance how to introduce new premises always feels a bit counterintuitive, and cancelling the premises always confuses me. Could you make a follow up on the rules and more on canceling the premises? anyways awesome video!

[marcourielmedinamandujano]

What you call "conditional proof" is what Mathematicians (and many logicians) know as "deduction theorem"