Contemporary Logic Part 2: Current Systems and Methods

[@jdm5570]

Thanks, man. You're a beacon of education in a world seemingly set on willful ignorance.

[@PahriPersonal]

you're welcome 😊;

[@capyhara-mk7qv]

@@ThommyofThennwho says that. Sems odly specific right?

[@ThommyofThenn]

@@capyhara-mk7qv You gotta watch Prof.'s Terrence Howard debunk vids. There are so many other horrifying gems in just those two episodes! I would laugh but i just can't in good conscience because some people actually listen to his " findings"

[@ThommyofThenn]

@@PahriPersonal np

[@daviddivad777]

i love it when a science educator gets into philosophy! awesome content.

[@hairychris444]

Remember some of this from 30+ years ago studying for my computer science degree. I always had problems, not with the logic itself, but when turning language or code into the notation. Did my head in.

[@The8BitPianist]

I'm looking forward to seeing the calculus and use of these symbols in the next tutorial!

[@mtshyna]

If you ever get into discrete structures of mathematics class just wait 😂

[@Oarijalab]

Bro, I wanted to tell you this for long! It is that please please continue your wonderful work of educating the people out there! I can't feel any more grateful to you for your immerse approach towards all fields of studies like chemistry, physics, astronomy, etc, etc, etc!!! I haven't seen anyone like you who's so shrewd and intellectual! I look upon you as my greatest inspiration and motivation to be erudite!

[@mtshyna]

As a first year computer science major, this made me cry tears of joy, and terror 😂 back to joy, then terror, and loop again

[@evilgirlypop]

Keep it up! Comp Sci is a challenging major, don't worry if you feel dumb or stupid. I've spent the past 4 years feeling stupid in this major.

[@corepersephone]

Thanks for making my own field more prominent. However, I think some formulas are very wild. I take issue with 8:55 in particular. I never ever saw quantifiers (e.g. E!) used with individual constants. Quantifiers can only bind with variables (x, y, z). It is also weird to formulate "it rains" with Rd, which would literally mean "Dave rains". In standard predicate logic, you would have to treat it rains as proposition (you can also conceive them as 0-ary predicates). You could formulate this as R->~Fd (If it rains, Dave does not wear flip flops). If you use E!x you could also formalise as E!x (R-> ~Fx) & x=d (There is exactly one person how does not wear flip flops if it rains and that this person is Dave). If you want to also formulate the temporal component never, you can also use a temporal logic ~ SOMETIMES (R & Fd) (There is no time such that it rains and Dave wears flip flops.) In general, I would use the temporal logic here. It comes closest to the propositional structure of the claim.

[@marcuskissinger3842]

Yup, my thoughts exactly. 8:37 is also an exceptionally poor translation.

[@citizencj3389]

Oh snaps!! Are we getting into Real Analysis???

[@aperson4512]

Real analysis seems like it's beyond the scope of this series, but it would be cool to see. I have been reading through Robert G. Bartle's "Introduction to Real Analysis" though, and it's pretty good. It starts with set theory then builds from there. It is much more approachable than Rudin's books too.

[@Wunjogenius]

Thank you! I love these series

[@TheKids422]

Thank you, I will support you on Patreon as much as possible.

[@hossamarafa2594]

There is a mistake in the formula at Min 9:02. Quantifiers bind variables only;therefore the d in ∃!d(Rd→~Fd) would be an alphabetic variance of ∃!x(Rx→~Fx) If, however, we wanted to talk about a specific constant element in the domain of individuals, then we don't need quantifiers Thus "Rd→~Fd" is probably what you meant say NB the two statements at 9:02 are natural language translation for ∃!x(x=d ∧ Rd→~Fd) But the uniqness quantifier is redundant here; since ⌜∃x(x=d∧Rd→~Fd)⌝ is logically equavelent.

[@taylorhornby7475]

I noticed that too

[@BollyWonka]

Thank you Dave!

[@foobarf8766]

This was great, I code a bit and so use formal/computation logic daily, but had no idea 'for all' had it's own mathematical (and unicode) symbol ∀ (U+2200). Looking forward to the next in this series!

[@mitzzzu_tigerjones444]

This is actually kind of important because if we can learn grammar on fun places that the Internet has for us… …Then it totally contradicts all the lame teachers that suck at teaching which tried to convince us that they were the best source and it’s now or never. I was told nothing but the real world won’t give me a pass… … That’s OK because the real world is teaching me how logic works and “teach” is kind of not. Sorry just don’t belittle a person and then expect them to learn Thanks for doing this stuff Dave🎉❤

[@TheCynicalCommentator]

I wish I knew about these episodes while taking my topics in contemporary math course :’-)

[@marcuskissinger3842]

There are a few errors throughout the video, but by far the most egregious is at 8:37. The first order sentence is not even close to representing the above natural language, as you can see by comparing the correct translation below the symbolization to what it was supposed to say above.

[@OREYG]

This is gold, thank you for making this video

[@BinaryHedgehog1]

It should be worth noting that different people might use slightly different variations on these symbols. The ∃ symbol for the system could denote either a group or an individual, and this was used in certain logical moves such as instantiation and generalization

[@jamiegallier2106]

Thanks Dave. ❤❤

[@CharmelBonzo]

My Holy Grail!❤🎉

[@brothertaddeus]

Hell yeah more predicate calculus!

[@ellispiper6313]

fascinating. Keep educating! Your way! Especially in a time of disinformation on levels never seen before, your content is crucial in helping folks use their brain and think for themselves. Set theory is a great way to visualize logic and, in my one semester of Stats/coding class, made understanding sets within sets (WITHIN SETS)[Within Subset of 'Sets'] a much easier concept to grasp.

[@ksp6091]

I've recently heard about "paraconsistent logic", a property of a system that can tolerate incoherences. Do you have anything on those ? Thanks

[@СергейМакеев-ж2н]

He mentioned "relevance logic" in passing. Relevance logic is one of the ways of doing paraconsistent logic.

[@theproofessayist8441]

those are hard - those are pretty hard - I'd think only people who do foundations of mathematics or logician like philosophers would handle that stuff.

[@mitzzzu_tigerjones444]

Wait…😮You’re saying that fuzzy logic is more than just a colloquial term😂❤

[@СергейМакеев-ж2н]

Yes, it's an actual thing, with many mathematicians working on it, and with real-world applications. Look up the Wikipedia article on it.

[@VergilSparda-kx6tx]

Explain morse codes.

[@TheLuckySpades]

"Some students are hardworking while kthers are lazy" I took that to mean there is at least one lazy student and at least one hardworking one, better formalized as \exists x \exists y ( ot(x=y) \and (Hx \and Ly)) If we want to preserve how you have H and L be exclusionary you can turn it into \exists x \exists y ( ot(x=y) \and ((Hx \and ot Ly) \and (Ly \and ot Hy)))

[@corepersephone]

I would also prefer to explicate the term students: \exists xy ~x=y & Sx & Sy & Lx & ~Hx & Hy & ~Lx. I left out the parentheses around conjunction, assuming negation has narrow scope by default.

[@LonkinPork]

Can we get Professor Dave _Explaining_ that tattoo on your left forearm? Looks like something involving geometry, it's intriguing

[@ProfessorDaveExplains]

i did! check "ask professor dave" series, i think #3

[@LonkinPork]

@@ProfessorDaveExplains oh damn, I'll check that out! Sorry, I'm a pretty recent Subscriber haha

[@ChildlezzCatlady]

👍🏼

[@dianetheone4059]

⭐⭐⭐⭐⭐

[@lancethederp]

It would be nicer if you bring back comprehension check here

[@carelhaasbroek1575]

No A negation is ! And is && Or is || => is a lambda function Jokes aside. I liked this topic in uni. Can't remember any of it tho.

[@KuemNyatoo]

Professor l need you to answer for me some questions now

[@Matin_MakiAbadi]

Professor you look very handsome 👍

[@do.notdisturb]

Unrelated but with Trump winning the White House are you planning on addressing claims made by RFK Jr.? I think that would do us a great service.

[@DanielSilveira-pn8dk]

Please fo an a video about the right (GOP) dragging our society into the the dark ages. With some hypothetical positives to undertake. I know a lot of us have lost hope. Thanks!

[@hossamarafa2594]

I'm no also sure how the " raining" is predicated of Dave The sense of a monadic predicate is a property and it's reference is the set of all objects that satisfy that property; thus ⌜Rd⌝ is semantically equivalent to d∈R Where R={x:x is raining} If you want to say it's raining you could use a zero-adic predicate, call it R Thus ⌜ R→~Fd⌝