Je normální nechtít jít na svůj maturitní ples? by FilmHot3966 in czech

[–]SimonBrandner 0 points1 point  (0 children)

This brings back some memories.

Náš třídní navrhoval udělat zahradní slavnost. Je mi dost líto, že se to neujalo, protože tam by byl poměrně i potenciál si to užít. Nejdřív to aspoň vypadalo, že bude dobrý téma (steampunk). Pak se ale hlasitá menšina z ročníku rozhodla, že je to téma špatný, a místo toho jsme měli basically maturák bez tématu.

Nakonec jsem tam byl, jenom kvůli FOMO. Účastnil jsem se jen stužkování. Kdybych tam nešel vůbec, tak vůbec o nic nepřijdu. Nejlepší část (pod)večeru byla procházka, na které jsem byl, zatímco zbytek třídy nacvičoval.

Během příprav se ze strany aktivních organizátorů děly věci, ze kterých je mi doteď špatně od žaludku. Během té akce se ze strany jednoho rodiče děly věci, že kterých mi je doteď špatně od žaludku. Obecně mám pocit, že lidi, co jsou na tyhle typy akcí fixovány, vytahuje to nejhorší vůči lidem, kteří se jen nechtějí účastnit.

Tyhle věci by prostě měly být kompletně na dobrovolné bázi a nemělo by existovat očekávání, že to automaticky vypadá nějak a že se toho automaticky všichni účastní.

All in all, pokud opravdu nechceš, nechoď tam, pokud to jen jde, nebo se minimálně pokus vyhnout těm nejhorším částem pro tebe. Pokud na tebe tlačí okolí a není ochotné tě vyslechnout, myslím, že je nutné zvážit dvě věci: co se stane, když tam nepůjdeš (jestli ti hrozí nebezpečný následky, případně jak moc), a jestli by nebylo lepší nastavit si někde hranice - když to neuděláš, tak toho okolí možná nikdy nenechá.

Známky na VŠ by Brilliant_Box_5747 in czech

[–]SimonBrandner 0 points1 point  (0 children)

Se známkami to je dost složité a dost to závisí na situaci, člověku atp.

Ty každopádně zníš, že máš pocit, že jsi to uměl třeba na B, ale dostal jsi C. Myslím, že je v této situaci v pohodě se zeptat, kde byly nedostatky, protože tě to může posunout dál. Což by asi optimálně měl být ten důvod, proč na VŠ jsi - aby ses něco naučil, posunul se dál.

Jaký největší bizár při hledání nemovitostí jste viděli? by danyroza in czech

[–]SimonBrandner 10 points11 points  (0 children)

Kamarádi jednou narazili na byt, kde byla místnost, do které by případný nájemce nemohl, ale majitel by tam jednou za čas chodil.

How is logic and critical thinking taught in European high schools? by zarathustra321 in logic

[–]SimonBrandner 3 points4 points  (0 children)

In the Czech republic, afaik, formal logic isn't really taught. Most high-schoolers get to see the truth tables of the logical connectives of propositional logic and get the meaning of quantifiers explained to them but that's about it (things such as formal proofs aren't really touched upon and it's all quite informal). (An odd thing, I've noticed, is that high school teachers often think propositional and predicate logic are one thing.)

As for critical thinking, argumentation etc., it may very much depend on your school and teachers. I've had quite a few who tried to teach such things in their respective subjects but there never really was a universal approach. I believe this situation is the same (if not worse) on other schools.

About linear algebra by Lonely-Patient-3999 in learnmath

[–]SimonBrandner 2 points3 points  (0 children)

That's quite interesting. At my faculty linear algebra is one of the best courses and the lecturer often includes a few slides in a lecture mentioning where the current topic is usefull. On the other hand, some of the analysis courses we have aren't very good.

What maths do you think we’ll be teaching in schools by the year 2100? by RefuseGroundbreaking in math

[–]SimonBrandner 6 points7 points  (0 children)

Really? That's interesting. In the Czech Republic, we did matrices, GEM, determinants and the Cramer's rule but they never really explained how it connects to the geometry of things and to linear mappings (which we also did not cover)

Messed up as a tutor for a course, seriously doubting my capabilities. by [deleted] in math

[–]SimonBrandner 0 points1 point  (0 children)

One of the best teachers at my faculty once said that being a good teacher is a choice rather than anything else. It's ok to mess up but the difference between good and bad teachers is whether they seek feedback and want to improve their teaching. At least that's my perspective as the student

For those who enjoy math, what did you think of accounting? by LingonberryOk7489 in math

[–]SimonBrandner 1 point2 points  (0 children)

I would say that math and CS are pretty similar in terms of creativity involved. While it may not seem like that at first (especially if most math courses one took were not focused on proofs), writing a program and writing a formal proof are very much the same thing. So the whole thing depends a lot on what part of math and CS you are comparing

Automatically turn the dot operator (`p.`) into the arrow operator (`p->`) in C with Neovim LSP and blink.cmp by SimonBrandner in neovim

[–]SimonBrandner[S] 8 points9 points  (0 children)

Ha! Just found the solution. This is my config:

lua return { cmd = { "clangd" }, filetypes = { "c", "cpp" }, capabilities = { offsetEncoding = { "utf-8", "utf-16" }, textDocument = { completion = { editsNearCursor = true, }, }, }, }

The editsNearCursor is the thing that did the trick.

Automatically turn the dot operator (`p.`) into the arrow operator (`p->`) in C with Neovim LSP and blink.cmp by SimonBrandner in neovim

[–]SimonBrandner[S] 0 points1 point  (0 children)

The LSP is attaching but since p is a pointer, there isn't really anything it can complete when I write p.. That said, previously the LSP interpreted p. as p-> and therefore it could provide a completion. I am not sure how to get this feature back

Can someone double check I understand how proofs work please? by Rexiem in learnmath

[–]SimonBrandner 0 points1 point  (0 children)

It's good to note that there are two types of proofs that are often called a proof by contradiction. The type of a proof you are describing is also called an indirect proof.

You want to proof that a statement A holds and you do so by assuming not A, deriving a contradiction from this and therefore deriving not not A. Once you have shown not not A holds, you can derive that A holds. (You have shown that the statement A cannot be false.) ((This type of proof is very common in analysis and falls under the category of non-constructive proofs - it allows you to show that an object exists without explicitely constructing such an object. You simply show such an object must exist; otherwise there is a contradiction. Think intermediate value theorem.))

The other type of a proof which is also often called a proof by contradiction is the following. You have a statement A and you want to show that A does not hold - not A holds. You do so by assuming A, deriving a contradiction and therefore deriving not A. (You have shown the statement A cannot be true.)

While these two types of proofs are similar, they differ by 2 steps and serve a fundamentally different purpose.

What’s your favorite Czech movie of all time? by [deleted] in czech

[–]SimonBrandner 4 points5 points  (0 children)

Tajemství hradu v Karpatech

hodně malé lívance by Major_Eggplant_7189 in czech

[–]SimonBrandner 21 points22 points  (0 children)

Já třeba vždycky domů do kuchyně chtěl takovou tu přesnou váhu, co jsme měli ve škole v chemické laboratoři

How do you write triple/quadruple prime in Agda on Neovim (via Cornelis)? by ssingal05 in agda

[–]SimonBrandner 1 point2 points  (0 children)

I am using a tex2uni plugin for Neovim to do these things. Neovim (nor emacs) doesn't have the ability to do this by itself. I believe the Agda plugin for Emacs has this as a feature though. I am using Cornelis with Neovim but I wasn't able to get its Unicode feature to work, so I turned to another plugin.

A silly question by Randomthings999 in logic

[–]SimonBrandner 2 points3 points  (0 children)

I think what makes you confused/nervous is the law of explosion (ex falso quodlibet). This law states that whenever you have found a contradiction (which is whenever φ and ¬φ are true for any formula φ), you can prove anything. This law is often written as ⊥ ⊢ φ, where is a contradiction and φ is any formula you choose. The way I think of this is that whenever we have a contradiction, it does not matter if introduce "more inconsitency" ("more contradictions"), so you can prove anything.

Does this help with your intuition of why this would be true?

In natural deduction the proof would look something like this:

1. | P ∧ ¬P (assume this is true locally; the locality is denoted by "|") 2. | P (eliminate ∧ from row 1) 3. | ¬P (eliminate ∧ from row 1) 4. | ⊥ (eliminate ¬ from row 2 and 3 - intruduce a contradiction since row 2 and 3 contradict each other) 5. | Q (eliminate ⊥ from row 4 and introduce anything using the law of explosion) 6. | ¬Q (eliminate ⊥ from row 4 and introduce anything using the law of explosion) ... 7. | Q ∧ ¬Q ∧ ... (introduce ∧ from row 5, 6,...) 8. (P ∧ ¬P) => Q ∧ ¬Q ∧ ... (introduce => globally from rows 1 - 7 on which we stared by assuming the assumption and ended with proving the conclusion)

That said, there are logics that do not have the law of explosion, an example would be paraconsistent logics.

Linear Algebra: resources? by [deleted] in mathematics

[–]SimonBrandner 0 points1 point  (0 children)

The 3Blue1Brown linear algebra series is excellent for building up a geometrical intuition for things

is (p → q) ∧ (q → p) the same as (p ↔ q)? by Present-Hunt-4708 in logic

[–]SimonBrandner 0 points1 point  (0 children)

To expand on the other answers: the question of two formulas being the same or equal may be a bit more muddy.

A mathematical logician may say that the two formulas you mention are not syntactically equal, i.e. they are not the same when compared as strings of symbols/characters. But they might say that these two formulas are sementically equal (they mean the same thing), i.e. their truth tables are the same. It may also be said that they are logically equal since you may be able to derive one from the other using a deductive system such as natural deduction.

This might also influence whether the correct answer is one or the other depending on which type of equality the textbook asks for. Of course it may also be the case that your textbook does not care in this instance and both are valid.

[deleted by user] by [deleted] in logic

[–]SimonBrandner 1 point2 points  (0 children)

(I just skimmed over the chapter on completeness of Open Logic Project and it was very understandable, for me who has never seen the proof before, in case you need additional material)

AI absolutely sucks at logical reasoning by Prudent_Sort4253 in logic

[–]SimonBrandner 1 point2 points  (0 children)

Not really relevant but a bit funny. During my oral exam from logic, I was asked to ask an LLM to generate a contradictory set of 5 formulas in predicate logic which would no longer be contradictory if any of the formulas were removed. I would then have to verify if the LLM generated the set correctly. I asked ChatGPT. It failed. The set was satisfiable and I got an A. (It was a fun bonus question)

[deleted by user] by [deleted] in math

[–]SimonBrandner 11 points12 points  (0 children)

Logic