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Claudia

 /dev/chat

General discussion for unix.stackexchange.com. If you have a q...
2
Claudia
Aug 23, 2022 21:48
tfw typo
port numbers are far too easy to typo ngl
Claudia
Aug 23, 2022 20:57
ok fair
Claudia
Aug 23, 2022 20:55
oh this would technically be in a professional capacity (the server's primarily intended to be used for business purposes) so it'd be on-topic for there
Claudia
Aug 23, 2022 20:28
i'm at a loss - is there something that could cause ssh -L to fail silently while simple interactive sessions would still work? ran `ssh -o ExitOnForwardFailure=true -fNTL $port:localhost:$port $host -vvv` and while it returns successfully (exit code 0 and everything), i also mysteriously am seeing `debug3: mux_client_read_packet: read header failed: Broken pipe` followed by `debug2: Received exit status from master 0` in the output

also would such a question be better suited for here or for server fault?
 

 Root Access

For all you Super Users out there. You have backups, right?
5
Claudia
Aug 23, 2022 21:48
port numbers are far too easy to typo
Claudia
Aug 23, 2022 21:48
tfw typo
Claudia
Aug 23, 2022 20:52
i'm at a loss - is there something that could cause ssh -L to fail silently while simple interactive sessions would still work? ran `ssh -o ExitOnForwardFailure=true -fNTL $port:localhost:$port $host -vvv` and while it returns successfully (exit code 0 and everything), i also mysteriously am seeing `debug3: mux_client_read_packet: read header failed: Broken pipe` followed by `debug2: Received exit status from master 0` in the output

also would such a question be better suited for here for server fault or for unix.se?
Isiah Meadows
Mar 2, 2020 00:58
How would I make sure those tags existed on that package provider?
Isiah Meadows
Mar 2, 2020 00:47
And what dependencies would NuGet need?
Isiah Meadows
Mar 2, 2020 00:46
I tried googling it and couldn't find anything that helped. I already tried that particular Medium suggestion, too.
Isiah Meadows
Mar 1, 2020 22:37
I've got this odd error message when attempting to install NuGet:

PS> Install-PackageProvider -Name NuGet -Force
Install-PackageProvider : No match was found for the specified search criteria for the provider 'NuGet'. The package provider requires 'PackageManagement' and 'Provider' tags. Please check if the specified package has the tags.

This is in an elevated PowerShell on virtually brand new hardware, BTW, so it's not likely anything to do with permissions.
Isiah Meadows
Oct 22, 2019 02:31
Still kinda wonder, though.
Isiah Meadows
Oct 22, 2019 02:31
Okay, never mind, it appears to at least be working on the target system. :-)
Isiah Meadows
Oct 22, 2019 02:23
The install DVD is not physically damaged, for context. It's a brand new drive that I'm hoping isn't DOA.
Isiah Meadows
Oct 22, 2019 02:20
I've got the strangest issue: I've got a DVD drive that showed up on my Mac when I put in a disk containing drivers and manuals, but when I inserted a Windows 10 OEM disk, it won't even show up in sudo diskutil list.
Isiah Meadows
Aug 22, 2019 09:27
@djsmiley2k Rebooted and it automatically did an fsck, and when I went back, the entries were gone. So it appears all is well now.
Isiah Meadows
Aug 22, 2019 07:29
And it's not one file, but about a dozen all at once.
Isiah Meadows
Aug 22, 2019 07:29
For context, my issue is on MacOS High Sierra.
Isiah Meadows
Aug 22, 2019 07:23
I've got the weirdest issue: I've got a file I can't even unlink. Tried not only rm -f $FILE but also unlink $FILE and then in Node.js via fs.unlinkSync(FILE). For the first two, I get an Invalid argument error and for the last I'm also getting the same EINVAL errno code. (The manpages don't state that as even possible for unlink, just unlinkat if you pass the wrong flags. And Node doesn't call unlinkat or anything else, just unlink.)
 

 Mathematics

Associated with Math.SE; for both general discussion & math qu...
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Isiah Meadows
Jul 9, 2019 00:25
It's more on-topic to CS.SE anyways. Sorry for the noise and confusion.
Isiah Meadows
Jul 9, 2019 00:25
Sorry. DFA = deterministic finite automaton
Isiah Meadows
Jul 8, 2019 23:46
It's really just I'm trying to convert arbitrary integer ranges like 2, 5, ... into DFAs based on their digits.
Isiah Meadows
Jul 8, 2019 23:44
I'll post a question on Math.SE with a better explanation of what I'm going for. My question wasn't quite accurate.
Isiah Meadows
Jul 8, 2019 23:44
Normally, I omit the dot, but I'm not a mathematician here.
Isiah Meadows
Jul 8, 2019 23:43
Yes. I meant $xs$. My bad - too used to programming languages.
Isiah Meadows
Jul 8, 2019 23:42
The degenerate cases of 1 and -1 for me are pretty obvious, as well as a few cases like 2. But I'm struggling to find any leads on a general solution. Admittedly, I'm not well-versed in number theory.
Isiah Meadows
Jul 8, 2019 23:40
Question: I've got triples like $(a, b, s)$ repesenting ranges of $\lbrace x * s : a \le x * s \lt b, x \in \mathbb{Z} \rbrace$ where $s \in \mathbb{Z}, s \ne 0$, basically (start, end, step), and I'm trying to figure out how to convert that to sets of digit sequences, like $(3, 20, 4)$ to $\lbrace \lbrace 3 \rbrace, \lbrace 7 \rbrace, \lbrace 1, 1 \rbrace, \lbrace 1, 5 \rbrace, \lbrace 1, 9 \rbrace \rbrace$, without evaluating the sequence directly.
Isiah Meadows
May 27, 2019 07:44
Oops, just realized a mistake here: I meant $\sum_{i=0}^{n-1}2^{2^i}$, not $\sum_{i=0}^{n-2}2^{2^i}$.
Isiah Meadows
May 27, 2019 07:02
In math notation, it's $\sum_{i=0}^{n-1}2^{2^i}$, which does make it sound slightly more complicated, but it only subtly looks different from $\sum_{i=0}^{n-2}2^i$ on the surface. I know they're not exactly the same and that the different exponent does make a big difference, but I didn't expect literally nothing to show up in basic Google searching. (And I don't know enough about number theory to know where to search for more information.)
Isiah Meadows
May 27, 2019 06:59
Speaking of weird questions, just stumbled into this. For something that sounds really simple in theory (the sum of the first N terms of the sequence where you start from 2 and square it each time), I can't find hardly any material on it.
Isiah Meadows
Apr 27, 2019 23:08
Ignore my question. I'm coming of the realization it's just not working how I would've hoped, so I'll just go with what I had before.
Isiah Meadows
Apr 27, 2019 23:06
"... and it's pretty obvious you can move the $x$ inside the radical" To clarify this in advance, I didn't mean literally move it verbatim, but via $x \sqrt{y} = \text{sgn}(x) \sqrt{x^2 y}$. (Hopefully, this was obvious, but I don't want to confuse people on what I meant.)
Isiah Meadows
Apr 27, 2019 23:01
Complicated, I know, but this is me trying to see if I can skip calculating Euclidean distance twice going from atan2 to something in terms of asin for a thing I'm working on.
Isiah Meadows
Apr 27, 2019 23:00
My hope is that I can somehow remove the polynomial from the bottom entirely, so I can then multiply the whole thing by a square root of another algebraic fraction.
Isiah Meadows
Apr 27, 2019 22:59
My expression happens to be in a form I can normalize to that, just the radicand happens to be a lot more complicated. In my case, I'm trying to figure out how to best simplify $\frac{x}{\sqrt{1 + x^2}}$, and so far, I've gotten to $\frac{x \sqrt{1+x^2}}{1+x^2}$, and it's pretty obvious you can move the $x$ inside the radical.
Isiah Meadows
Apr 27, 2019 22:55
Is there a standard way to divide radicals by polynomials? Stuff like $\frac{\sqrt a}{1 + b^2}$?
 

♦  Logic

This room is meant for discussion about logic, including found...
1
Isiah Meadows
Apr 23, 2019 13:01
👋
Isiah Meadows
Apr 23, 2019 12:51
That is true, but my goal isn't entirely about proving them from the algorithms themselves. A lot of languages (like TypeScript) get by with a fully deductive type system, and induction is certainly far from universal.
Isiah Meadows
Apr 23, 2019 12:49
Numeric calculation as computers implement them can obviously be done within that, which is part of why I'm not ready to dismiss it.
Isiah Meadows
Apr 23, 2019 12:48
And I do agree that for some things, it might very well be more natural. But I want to see first how much can truly be done or at least emulated in ACA and similar.
Isiah Meadows
Apr 23, 2019 12:48
$a + b \mod 2^32$ is equivalent to $a - (2^32 - b) \mod 2^32$, so it's not like you can't also model it using purely subtraction. Stuff like that is why I find Dan Willard's research an interesting lead nevertheless - it relies on subtraction and division as primitives, and with modular arithmetic, you can still model modular addition and multiplication in terms of subtraction. If the "modular" part of it can still fit within that framework, the lead still can work.
Isiah Meadows
Apr 23, 2019 12:44
And also, computers don't model addition in a way that requires nearly as much expressivity as, say, continuous integration. It's all discrete and finite.
Isiah Meadows
Apr 23, 2019 12:42
I'm looking at the single-threaded side of things and bugs common to that.
Isiah Meadows
Apr 23, 2019 12:42
That is true, but it's a separate issue to what I'm looking to address. (In fact, work has been done to partially solve that in the form of substructural logics.)
Isiah Meadows
Apr 23, 2019 12:41
Fair.
Isiah Meadows
Apr 23, 2019 12:40
I've seen Prolog, Coq, and the like.
Isiah Meadows
Apr 23, 2019 12:39
@user21820 I'm aware of what's done before, and I'm aware of the incompleteness theorems. And I'm aware what the restrictions mean. BTW, infinite work on infinite input is okay. My concern is with finite input causing indefinite work, and also, I'm questioning the utility of things like Ackermann's function in practice - this is aimed not at highly theoretical stuff but at more practical things like reacting to UI events and such.
Isiah Meadows
Apr 23, 2019 10:21
So the use cases might not seem immediately obvious from a pure mathematics or logic standpoint, but I'm coming at this from an engineering standpoint where something like this could potentially set the stage to fix a lot of problems within the industry.
Isiah Meadows
Apr 23, 2019 10:16
So even though these theories are much weaker than what modern mathematics are based upon, the little I've seen still make it seem potentially useful in enforcing invariants preventing various bugs in practical programs. (It's worth noting that two's complement arithmetic in machines is implemented as an operation from two tuples of booleans to a single tuple of booleans, usually all of the same size. Floating point is also similar.)
Isiah Meadows
Apr 23, 2019 10:11
@user21820 Sorry for the late response, but the main application I have in mind is in creating a programming language leveraging it to ensure formal soundness and completeness while prohibiting infinite loops, making memory leaks much harder, and the like, all common areas of program bugs. Infinities exist in mathematics, but they don't really exist in computing without assuming infinite time and/or memory, two things that obviously don't concretely exist.