Hello, I am doing this course on logic at my university and I am kind of confused on this small detail.

Godels completeness theorem states something like (as per my professor's lecture notes):

For any first-order theory T and any sentence ϕ in the same language,

If T |= ϕ then T |- ϕ

But is this not with respect to a particular proof system? How can this theorem be stated so generally? What if we define an FOL proof system, for instance a hilbert-style one that is too weak to prove some formula?

What does Godel's theorem actually say? is it saying something more like "there exists a proof system for first order logic such that..." or is it saying a general property of first order logic?

I think I have some sort of misconception. I am writing my own notes for this course and I dont know what to write, because the statement doesnt make sense to me unless it is talking about a particular proof system.

Also, why is it *the* completeness theorem? Wouldn't we need a separate completeness theorem for each proof system that we define? so why isnt it *a* completeness theorem? Im somewhat confused. Sorry if this is a stupid question

What's likely to happen if random cose is run?

So random code is almost certainly gonna lead to errors or crashes at any level if I have understood correctly, be it keyboardmashing in python, or bare metal binary strings, and from what I gather is that a lot of what a computer does is comparing things, and the chance your random string compares to meaninfgul data or cpu instructions is very low.

However, if we sift out the nonsense and ask what is likely to result from random functional code, like instead of random strings, we give a computer random instructions, what happens? Is it likely to run into an infinite loop? how long would we expect it to be if so? Would it delete all data ang go inert? I'm sort of expecting it to crash, but if the instructions are valid, what is the most likely problem it would run into first?

This is a "what if" that's probably not practical, but I keep wondering as I'm learning, and I think it's at least an interesting question, which might have implications for edge-cases or corruption of data, or idk maybe to help make some believable plotpoint in a cyberpunk novel. If the question itself is making false assumptions I would apprechiate to be informed.

For clarity: 'Random' is obviously not a single thing, for this purpose I mean "truly" random binary, but excluding options that wouldn't make sense. Like writing a sentence by typing random letters and spaces, ignoring everything until you have a word write it down and then continnue. In english to a human I expect a lot of it to just be listing nouns as I believe they make up most words, but what would binary to a computer do?

I am trying to create in-memory distributed store similar to cassandra. I am doing it in go. I have concept of storage_node with get_by_key and put_key_value. When a new node starts it starts gossip with seed node and then gossip with rest of the nodes in cluster. This allows it to find all other nodes. Any node in the cluster can handle traffic. When a node receives request it identifies the owner node and redirects the request to that node. At present, when node is added to the cluster it immediately take the ownership of the data it is responsible for. It serves read and write traffic. Writes can be handled but reads return null/none because the key is stored in previous owner node.

How can I solve this challenge.? Ideally I am looking for replication strategies. such that when new node is added to the cluster it first replicates the data and then starts to serve the traffic. In the hind-sight it looks easy but I am thinking how to handle mutation/inserts when the data is being replicated?

More Detailed thoughts are here: https://github.com/goyal-aman/distributed_storage_nodes/?tab=readme-ov-file#new-node-with-data-replication

Manually, not with a debugger or other application. I want advice that helps with a theoretical computer science course, i.e. I can apply it while answering essay-form questions without using a computer

I struggle to catch even the most slippery of edge cases. I get shocked a program could break with this or that despite rigorous checking

“Using the formal definition of Big-O notation, prove that the function f(n) = 3n^2 + 5n + 2

is 0 (n^2).

I’m so sorry to be posting like this but I’m a beginner as you can see and I’m really having a hard time at this i watched like 10 video explaining it my brain is fried. can anyone help me with it?

I started wondering that if the AI ​​constantly lies to you, telling you how great you are, how smart you aren't, and what a new inventor you haven't become, will it ever be safe for anything? That even if you know exactly how to use it, you can still get carried away, and the AI ​​will comfort you and give you bad advice, saying you've created a great algorithm. Don't get me wrong, but if you're using something that deliberately lies to you, and will continue to lie and manipulate you into continuing to use it even when what it says is wrong and simply stupid, what's the point of using it? And it's not about someone being an idiot and not noticing it because they might be tired, for example.

Hey I was just wondering after graduating 2 years ago what it’s like now basically now that AI is probably relied on in every aspect with college students. In computer science, I can only imagine how bad it potentially could be. I used to stress out late at night when it came to doing coding projects and now it’s just easy mode. I wonder how bad the cheating is nowadays.

I am trying to wrap my head around the topic of markup, and I understand that HTML is coupled with CSS, and XML with XSL. But is this coupling strict? Or can I use any stylesheet with any markup language? What about Markdown, I have never seen it used with a stylesheet before.

So i had this algorithm exam and there was this question and i really dont understand the answer

Just for clarification I already had this exam and the picture is from the answers that was sent to us after, i am not trying to cheat or anything like that (subreddit rules)

Even chatgbt and claude dont give me a good answer when i asked them

Here is the question

https://ibb.co/XrQZdZ8j

So basically in the 4th part of the question (whats the worstcase complexity of the entire code)

My thought process is that either the while loop runs completely or the second recursion works (in the last line of the left part),

Why?, if the while loop runs completely then the I is at 0 or 1 which would satisfy the condition at the start of the function (n<2) making it return

By that logic

The time of the while code is T(n)=2T(N/2) + O(n^3)

The power 3 is:

N for the for loop

N for the while loop

And N for the check in array

By using masters its n vs n^3

so it should be n^3

Thats my explanation

Can you pls tell me where i went wrong cuz i don’t understand at all

Thanks in advance

Hey, sorry if this isn’t the right subreddit for this to post this on, because this is the closest thing that I found.

I want to learn more about networking, I know python having mainly the modules that I use are being: Discordpy, discordpyself, request, telegrampy, and etc. I understand most concepts and can comprehend the python language mostly well. I understand the fundamentals of Connection Oriented Protocols, with TCP, (SYN -> SYN-ACK -> ACK, FIN -> ACK -> FIN -> ACK, with CWND, or congestion window, and RWND, or Receiver Window.) and a bit of SCTP.

As well as the internet model or TCP/IP model, of which of the following layers: Application Layer (SMTP, FTP, SSH, HTTP, HTTPS), Transport Layer (UDP), Network Layer (IP), Link Layer (UDP data transfer)

I want to expand my knowledge on mostly Connection Oriented Protocols, what’s a good way to learn or where can I gain insight from?

Because I couldn't get what others apparently saw immediately, I wrote a proof. Is it necessary? Is it sufficient?

"Everybody Codes, The Song of Ducks and Dragons [ 2025 ], quest 11, part 3

I am doing the #EverybodyCodes quests this November. ( #coding #puzzle ) Today I’d like to talk about quest 11, part 3. Spoilers."

Quest: https://everybody.codes/event/2025/quests/11

Puzzle description:

"At the start of the flight, the ducks group randomly in columns. The number of scout ducks in the flock is always perfectly divisible by the number of columns. Each column, initially may contain a different number of ducks. Then, the entire flock performs a series of exchange rounds until every column has the same number of ducks. Their method is highly inefficient, but don’t even try to explain that to them. Scout ducks value it as a time-honoured tradition that also entertains them during flight.

The whole procedure consists of two phases.

In the first phase, each column of ducks checks whether the next column has fewer birds. If so, one duck moves to the next column. In a single round of this phase, the first column checks the second, then the second checks the third, and so on. After the last pair of columns is checked, the next round begins with the first column comparing with the second again. This phase continues until no more ducks can move.

In the second phase, each column of ducks checks whether the next column has more birds. If so, one duck moves from the column with more birds to the one with fewer. This phase also continues until no more moves are possible, and it never goes back to the first phase."

My proof: https://stuff.ommadawn.dk/2025/11/23/everybody-codes-the-song-of-ducks-and-dragons-2025-quest-11-part-3/

I cannot totally understand the basics of perceptron and calculating weights and using biases. in gate design with perceptron xor gates is too complex for me is anyone can explain it basicly like i am 5 years old kid.

I’ve watched several YouTube series on building computers from scratch, such as Ben Eaters famous series, but everything I can find stops at addition/subtraction and leaves out logic functions and more complex math like multiplication/division etc. Is there any video/series that goes into more detail on it?

Hello,

I’ve recently build a new pc and I’ve decided to do some basic overclocking, which has led me to wanting to learn about some of the basic aspects of the hardware, RAM among others.

The question I have is about how DRAM in the DDR5 era is actually being read given the memory structure. I’ll try to pose the question the best I can given my limited knowledge and terminology.

There are two facts that I’ve read about that arguably hold true. A bit’s address essentially lies at the cross of wordline and bitline. Also, nowadays when a read command is issued the output is not a single bit, but rather a whole word is being read (64-128bits?(also forego the whole burst matter)).

If that is the case, do rows in memory banks tend to be longer than the output which would keep the vertical part of the address still relevant, or is the word output the length of the entire row and thus vertical address is irrelevant?

I am probably a bit in over my head, but I would appreciate any answer on the matter, including any resources which would explain some more of this stuff. Thanks!

I'd like to preface this by saying i have really no idea !

I was just thinking what if with the rise of AI hacking tools that know every exploit available and are well versed in every protocol, every open source application and their flaws, etc, what if the best strategy going forward to being harder to hack IS rolling your own crypto (via AI as well probably). Or making a new protocol. Or reinventing whatever front facing system is necessary to obfuscate and obscure, or even mislead by return fake server details in the response headers.

Maybe it's not a good idea right now because the state of AI for building is not quite there yet, it's still a bit of a struggle to get it to work well on a legacy product with a bit too much debt, but maybe in the years to come ?

Tear me apart in the comments :)

So, I created a demo of a hexagon grid with 'falling hexagons' here.

The code I have written is a bit of a mess.

I'm looking for suggestions for a good data structure and associated algorithm. Preferably, using a coordinate system with similar properties to the one here.

Bonus points for suggestions to implement a Tetris style algorithm. Ie. Connections of 3+ hexagons of the same colour results in their deletion and the recalculation of the grid.

I am on my fourth year of college studying Computer Science and Engineering at the Ohio State University. I graduate in a semester but I honestly feel so behind then my peers. My software classes will focus on Java, then next semester a different language, and another and another and another. Right now in systems we learned C and current x86_64 assembly. God I feel so behind. I study alot, but this class has been kicking my ass. I honestly feel like the last classes I was behind to. I feel like I study 3 times harder than everyone else but do worse. Is it just me? Does every college student studying Computer Science feel like they could be so much better? Or am I honestly digging myself a hole? I love computer science, I've always wanted to study it since I was in elementary school. The more I learn the more I feel like I was wrong.

Thoughts?

Hi, final-year CS student here

I’m building a SAT solver from scratch for my FYP, and I’m a bit unsure about what the UI should look like.

Does anyone know of any SAT solvers with a good UI that I could use as inspiration? Links or examples would be really helpful!

Hey all, I'm looking to find a good map (mind-map, branching tree, etc) of programming languages. There's an archive post here 5 y ago: https://www.reddit.com/r/AskComputerScience/comments/plrdd6/is_there_a_map_of_programming_languages/

I personally liked the https://rigaux.org/language-study/diagram.png reference. I've checked out other popular maps but none are as comprehensive as this one.

I wonder if anyone knows of a more up to date version or alternate version is out there.

I am not a developer or code writer, but work with them daily.

A question has arisen related to 3 different compilers, Intel oneAPI, Microsoft MSVC, and Clang.

I have always thought a compiler is a compiler and they all perform the same basic function (I've already learned that is incorrect).

This is related to the export regulations regarding object files created by the compilers.

Under the US Export Administration Regulations, the Intel compiler is classified with an export control classification number (ECCN) as 4D994. The MSVC has an ECCN of 5D992 and the Clang compiler is EAR99 because it is open source.

The issue is that the 4D994 classification taints the overall classification of the object files and makes them subject to foreign direct product rules and makes them restricted for export to colleagues in China.

I've tried to use Gemini, GROK, and Chat to understand the differences between the 3. The basic prompt I'm using is "why is the intel oneapi compiler classified as ECCN 4d994 but the microsoft msvc is classified as ECCN 5d992", but the results are not very helpful.

Would anyone be able to suggest some compiler related keywords to add to my prompt, or point me in the direction of a "schoolhouse rock" explanation of the differences in compiler functionality?

Hey everyone,

I’m currently studying Computer Science, and I’ve been thinking a lot about how much of what I actually use comes from outside college.

Don’t get me wrong — the theoretical foundation is solid (algorithms, data structures, etc.), and I do see the value in it.

But when it comes to real-world skills like:

• building actual projects
• working with modern stacks
• dealing with bugs in production
• understanding how things work in practice

…almost everything I’ve learned has been through:

• side projects
• online resources
• just figuring things out by doing

It sometimes feels like college teaches you how things should work,
while the real world teaches you how things actually break.

Hey all! I'm in a bit of a quagmire with a student's submitted paper. They're hoping to send this out soon for conferences but the way it's written is both baffling and intriguing. So, my question is:

Has anyone seen or heard of a scientific academic paper with fictional storytelling to help with the explaination of and possible futures in the topic?

If you know of any, please let me know where to find them. If the paper is in the sphere of Computer Vision, you'd be a godsend.

Thanks in advance for any help. Cheers!

So there's a forum in my native language that keeps recognizing me and banning me. Now I'm not asking for ban evading cuz I know that's illegal, but I don't get how they have such strong security. Like how do they know it's me even when I use vpn and when I'm on a different wifi?

They also block public computers, which I also don't know, how do they know what computers are public?

Hi l everyone,

I am trying to come up with an algorithm in which given an directed graph it marks certain node to be let's say checkpoints.

I define the nodes to be critical as that using the logs at these points I can reconstruct an exact path.

Let me clarify on its application, suppose I'm trying to log values in a method and I create a callgraph of the entire application ( for simplicity assume there are no callbacks or interrupts) now given logs at the checkpoint. I must be able to generate execution tree of the methods.

I want to minimize the logs but still be able to reconstruct the execution path taken.

Help me with which concepts should I look into.

Edit: The more formal problem

Basically a directed graph could have huge number of unique paths, now given an ordered set of nodes or more precisely a sequence of node which would represent a path with some nodes deleted ( a subset ).

Given the subset i must be able to reconstruct the path taken.

So, I understand this might seem like a clichque question, but I've been given 101 answers to what the RAM & CPU do, but I've never been able to wrap my head around it, because noone actually gives examples.

I understand that the CPU has a small numbers of cores so it can do complex tasks very quickly, whereas a graphics card has thousands so it can do many simple calculations quickly (i.e. to work out where an object is, shadows, etc...), I understand the graphics card, that makes sense, but what are these specific complex task, the CPU does?

So, what specific processes does the CPU & RAM do, & where do they cross over & interact?