is x in βˆ€x[βˆƒx[x=n]] a bound or free variable?

As far as I can understand it (correct if i am wrong here as this is my own estimation, not something Iv'e read! If I am wrong then I presume it’s undefined) the above x is any natural number if n is defined as a natural number. A variable is bound by one quantifier but what happens with two? I havent been able to find the answer to this via google.

Thank you in advance guys!!

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πŸ‘€︎ u/Hypeirochon1995
πŸ“…︎ Jun 25 2020
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Free and bound variables in Lisp - a great definition from SICP eli.thegreenplace.net/200…
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πŸ‘€︎ u/eliben
πŸ“…︎ Sep 23 2007
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Lambda Calc: Free vs Bound Variable

So I understand in this expression:

Ξ»xy.xu

that x and y are bound and that u is a free variable.

However, what if you have an expression like this

(Ξ»uv.v)(Ξ»x.ux)

I can tell that u and v are bound in the first expression, but in the second expression u is a free variable.

So if the question is to determine the free variables and bound variables would the answer be:

Bound: u,v,x
Free: u

EDIT: or would I be expected to alpha rename u in the first expression to something else so I could distinguish between them?

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πŸ‘€︎ u/rawmeniscus
πŸ“…︎ Mar 03 2019
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Differences between sigilless and sigilled variables that are bound to

As far as binding is concerned, I can see a few differences between sigilless and sigilled variables:

  • Sigilless variables can be bound to any type of values since there's no sigil involved. On the contrary, sigilled variables can only be bound to values the sigil dictates (e.g., $ to a Scalar value, @ to a Positional value, and % to an Associative value).

    my \any-scalar = 1;
    my \any-posit  = (1, 2); 
    my \any-assoc  = %(:1one, :2two);
    
    my $only-scalar := 1;
    my @only-posit  := (1, 2);
    my %only-assoc  := %(:1one, :2two);
    
  • Sigilled variables allow you to have different namespaces due to the different sigils; thus you can use the same identifier for different variables. This isn't the case for sigilless variables.

    my $foo := 1;
    my @foo := (1, 2);
    my %foo := %(:1one, :2two);
    
    my \bar  = 'bar';
    my \bar  = 1;       # Redeclaration of symbol 'bar'
    
  • Sigilled variables give you an idea of the type of valued bound to them. This isn't the case for sigilless variables.

    my $x := 1; 
    my @y := (1, 2);
    my %z := %(:1one, :2two);
    
    my \x = 1;
    my \y = (1, 2);
    my \z = %(:1one, :2two);
    

I know the value bound to @y type check against Positional, and @z type check against Associative; for $x is a bit more difficult because Scalars are transparent containers, and thus a $ "variable" could be bound to anything.

For x, y, and z, there's no way to know from a glance; you'd need to introspect them.


I've a few questions:

  • Is there something I'm missing here? Or something that I got wrong?

  • What criteria do you use to declare a bound variable sigilless or sigilled? For example:

    my \foo  = 1;
    my $foo := 1;
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πŸ‘€︎ u/ogniloud
πŸ“…︎ Dec 15 2020
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What am i supposed to do when one of the bounds has a variable that isnt going to be integrated in respect of? Im lost, how do i solve this?
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πŸ“…︎ Jun 14 2021
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lisp-extra-font-lock - Highlight bound variables and quoted exprs github.com/Lindydancer/li…
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πŸ‘€︎ u/trimorphic
πŸ“…︎ Oct 22 2020
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Can someone explain where my reasoning went wrong here? why does the second fundamental theorem not work in this situation if the top bound is a variable and the bottom is constant?
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πŸ‘€︎ u/saucysauce15
πŸ“…︎ Dec 15 2019
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Question about free/bound variables when dealing with quantifiers.

I'm having some trouble learning the restrictions on free/bound variables when dealing with rules of inferences involving quantifiers such as Universal Instantiation, Existential generalization, Universal generalization, and existential Instantiation.

I do not understand the intuition behind all of these rules as of yet, as far as I understand these are the restrictions:

Let #u be a proposition or propositional function, and #v denote replacing every free occurrence of u in #u by v. Then the restrictions are:

UI:

  • Forall free occurrences of u in #u, v must be free in #v in the same place.

  • The instantiating variable may already be free in u.

EG:

  • v is free in #v everywhere u is free in #u

EI:

(let p be a statement derived from #v)

  • v is free in #v everywhere u is free in #u

  • The variables v does not occur free in p or any statement leading to p within the scope of the assumption.

UG:

  • v is free in #v everywhere u is free in #u

Is this correct to the full extent?

EDIT: There is also one subtly that I am unsure about:

is it true that

(x)(exists.y)[ #xy ] iff. (exists.y)(x)[ #xy ]

if not what is the difference in meaning?

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πŸ‘€︎ u/yyttr3
πŸ“…︎ Jan 07 2015
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What type of regression could I use in which the outcome variable could be any value bound between -1 and 1?

Not much more to add really. I have an outcome variable in which the scores are bound to -1 and 1, and I'd like what type of regression I can use that employs that boundary. That is, I recognize that I could just use a good old fashion OLS regression, but I don't feel it's proper for the data that I have.

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πŸ‘€︎ u/AllezCannes
πŸ“…︎ Jan 24 2019
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Bounds on dependent truncated random variable with given mean and variance

I have two random variables X and Y with given (mean, variance) as (mu_x, sigma_x^2) and (mu_y, sigma_y^2), respectively. These random variables have their truncated counterparts: X* = max(0,X) and Y* = max(0,Y). We know the mean and variance of the truncated counterparts too: (mu_X*, sigma_X*^2) and (mu_Y*, sigma_Y*^2).

Can we comment anything on the covariance of the truncated random variables (i.e., E[X*Y*] - E[X*]E[Y*])?

Some conditions:

  1. The distributions of the original or the truncated random variables are not available.
  2. The variables may or may not be dependent because of the setup of the underlying experiment, so bounds assuming independence are not useful.
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πŸ‘€︎ u/jinesl
πŸ“…︎ Oct 20 2019
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4.26 Set Texture2d Variable No Longer Updates Bound Widget Brush Image

I upgraded from 4.21.2 to 4.26. My main and only widget with a bound brush variable no longer updates the Brush Texture when the bound variable is changed. I can see that the variable does receive the proper texture reference however the widget image remains white. (Top image). I was however able to update the image using the Set Brush From Texture (Bottom image).

Why is my Texture2D bound variable not updating the widget brush?

https://preview.redd.it/d9c5b8eyxoe61.png?width=1326&format=png&auto=webp&s=6d224d9ed3908f668db402a5218273ea71fee406

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πŸ‘€︎ u/frolurk
πŸ“…︎ Jan 31 2021
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In "~βˆƒx (x)", is the variable x bound by the negated quantifier?

Asking for metaphysics purposes- Quine's idea of "to be is to be the value of a bound variable", can you be bound by a negated quantifier?

EDIT: I see I got a downvote: if this is an extremely stupid thing to be asking, please tell me! I feel I may have completely got the wrong end of the stick here. Thanks in advance. :)

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πŸ‘€︎ u/santoniusmurillo
πŸ“…︎ Mar 19 2020
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Any way to reference lexically bound variables via symbol or string?

Hi,

I cannot find the answer anywhere, but I have to think it exists. Perhaps I am not using the right nomenclature. I have a closure (let bound) that needs to report internal variable status (not all of it, but key ones as part of a way to get insight into the running state of a model, which this closure and it's values represent. I am having trouble finding a way to return the names (for example as keys in a hash-table and their values). For example I would like to have a list of symbols that refer to the closure lexical variables that populate both the NAME of the variable and its corresponding VALUE at that moment in time:

(loop for varname in '(active-cycles shape calculated-decay cycle-time  )
  collect (cons varname (eval varname)))

In the above example, this loop form ideally would return a list of conses with the name of the value being returned and the variable. It could also be a hash-table. It ultimately will need to be turned into JSON to send to an analysis system. If it were three or four variables this wouldn't be an issue. But since these values need to be reported out regularly from within the closure, I need some way to efficiently do this.

Thank you for any guidance...

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πŸ‘€︎ u/lars-by-the-sea
πŸ“…︎ Apr 29 2020
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Stop using a dynamically bound 'generated-autoload-file' variable gitlab.com/ganserl/emacs/…
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πŸ‘€︎ u/negativeoilprice
πŸ“…︎ Oct 02 2020
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[Q] Formula for the upper bound on the expected error of the estimated mean of a random variable from n-samples. Is this formula documented anywhere? Is it even useful at all?

I was playing around with equations and I found this possible interesting inequality that can be applied to any random variable, but I'm not sure if there's an easier (and possible trivial) way to obtain what I got.

Let's say we have any random variable X with mean ΞΌ and variance Οƒ^2. And let's say we are allowed to sample it n times to get samples x_1, x_2, ..., x_n. And just like many times in statistics we try to estimate the mean from the samples, and let's say in this problem we're interested in the expected error (or an upper bound at least) of how wrong our estimate is from the mean,

As in define an error term e=|(x_1+x_2+...+x_n)/n - ΞΌ|, and we want to find an upper bound on E(e). I spent a lot of time googling and looking at different concentration inequalities in Probability theory and I got the following

P(|(x_1+x_2+...+x_n)/n - ΞΌ| > epsilon) <= min(Οƒ^2/(n*epsilon^2), 1) [from Chebyshev inequality]

Then since the term in the expectation is always positive, using this formula:

E[|(x_1+x_2+...+x_n)/n - μ|]= \int[P(|(x_1+x_2+...+x_n)/n - μ|>x)dx] from 0 to ∞

<= \int[min(Οƒ^2/(n*x^2), 1) dx] from 0 to ∞

<= 2Οƒ/sqrt(n)

So if we can sample X n times then on expectation the error of the estimates mean will be at most 2Οƒ/sqrt(n) which I think is very interesting and I can't find this fact anywhere else. And I can't figure out if it's because it's not actually interesting or if this inequality (or possibly something even tighter) can be achieved trivially using another inequality or that possibly I just didn't search hard enough.

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πŸ‘€︎ u/master3243
πŸ“…︎ Nov 18 2019
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SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens. Any clue where I've gone wrong
if (isset($_POST['submit'])) {
  try {
    $connection = new PDO($dsn, $username, $password, $options);
    $user =[
      "id"           => $_POST['id'],
      "roomname"     => $_POST['roomName'],
      "carpet"       => $_POST['carpet'],
      "lengthA"      => $_POST['lengthA'],
      "lengthB"      => $_POST['lengthB'],
      "lengthC"      => $_POST['lengthC'],
      "lengthD"      => $_POST['lengthD'],
      "underlayCost" => $_POST['underlayCost'],
      "gripperCost"  => $_POST['gripperCost'],
      "roomNotes"    => $_POST['roomNotes'],
      "clientID"     => $_POST['client_fk'],
    ];

    $sql = "UPDATE rooms
            SET id = :id,
              roomname = :roomName,
              carpet = :carpet,
              lengthA = :lengthA,
              lengthB = :lengthB,
              lengthC = :lengthC,
              lengthD = :lengthD,
              underlayCost = :underlayCost,
              gripperCost = :gripperCost,
              roomNotes = :roomNotes,
              clientID = :client_fk
            WHERE id = :id";

  $statement = $connection->prepare($sql);
  $statement->execute($user);
  } catch(PDOException $error) {
      echo $sql . "<br>" . $error->getMessage();
  }

So Ive been trying to set up an updating form that updates the database, however I keep getting an error that the number of parameters binding arent equal. I can't seem to figure out what I've missed. Im new to php so I'm not the best at debugging my own code but from what ive seen online I havent missed any colons etc.

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πŸ‘€︎ u/abunavsa
πŸ“…︎ May 21 2020
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kOS do not recognize default Bound variables

Hi everyone! Im new to kOS so I was learning on this ?official? Quick Start Tutorial. Im stuck at part where I should use kOS script to make my ship launch (hellolaunch.ks). When I run copy-pasted code, countdown will do its thing but when comes to staging, error comes (pic). I tried using just MAXTHRUST instead of SHIP:MAXTHRUST but without any luck. Also at the begging of script is thrust locked to 1, but thrust of ship is not modified.

What am I missing? Any suggentions what can be wrong here?

https://preview.redd.it/ftysio8y8ht31.png?width=380&format=png&auto=webp&s=c6d7f85fc151fe3046636bda1c6a70ae41df06bb

//hellolaunch

//First, we'll clear the terminal screen to make it look nice
CLEARSCREEN.

//Next, we'll lock our throttle to 100%.
LOCK THROTTLE TO 1.0.   // 1.0 is the max, 0.0 is idle.

//This is our countdown loop, which cycles from 10 to 0
PRINT "Counting down:".
FROM {local countdown is 10.} UNTIL countdown = 0 STEP {SET countdown to countdown - 1.} DO {
    PRINT "..." + countdown.
    WAIT 1. // pauses the script here for 1 second.
}

UNTIL SHIP:MAXTHRUST > 0 {
    WAIT 0.5. // pause half a second between stage attempts.
    PRINT "Stage activated.".
    STAGE. // same as hitting the spacebar.
}

WAIT UNTIL SHIP:ALTITUDE > 70000.

// NOTE that it is vital to not just let the script end right away
// here.  Once a kOS script just ends, it releases all the controls
// back to manual piloting so that you can fly the ship by hand again.
// If the program just ended here, then that would cause the throttle
// to turn back off again right away and nothing would happen.
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πŸ‘€︎ u/IAmYzii
πŸ“…︎ Oct 19 2019
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Reverse Repo Update! New reverse repo counterparties effective 8/26/21:Federated Hermes Capital Reserves Fund, Federated Hermes Municipal Obligations Fund, Federated Hermes Tax-Free Obligations Fund, Northern Funds - U.S. Government Select Money Market, Schwab Variable Share Price Money Fund

Reverse repo counterparties list updated

The following have been added to the list of reverse repo counterparties, effective August 26, 2021.

  • Federated Hermes Capital Reserves Fund
  • Federated Hermes Municipal Obligations Fund
  • Federated Hermes Tax-Free Obligations Fund
  • Northern Funds - U.S. Government Select Money Market Fund
  • Schwab Variable Share Price Money Fund
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πŸ‘€︎ u/Dismal-Jellyfish
πŸ“…︎ Aug 26 2021
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Can’t seem to get a lower bound on my u variable, maybe I’m doing this wrong?
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πŸ‘€︎ u/toms_123
πŸ“…︎ Dec 08 2019
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Inequalities that provide bounds on correlations between variables?

So I've been thinking recently that I don't have a clear sense of how high COR(X,Y) and COR(Y,Z) can be while preserving COR(X,Z) = 0, and I feel like I generally lack intuition for why correlation distance (1-correlation) violates triangle inequality. (I found a counterexample, but that's not my point).

I feel like there's some general structure below the surface I'm standing on that I'm not quite grasping. Any thoughts on resources for inequalities in correlation?

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πŸ‘€︎ u/TissueReligion
πŸ“…︎ Oct 23 2018
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Bound by Flame (May 9th) Runs At Native 1080p on PS4, Has A Variable 30-60 Frame Rate gamingbolt.com/bound-by-f…
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πŸ‘€︎ u/Element0f0ne
πŸ“…︎ Apr 28 2014
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Beaconless PAT and adaptive beam control using variable focus lens for free-space optical communication systems | APL Photonics (8th Feb 2021) aip.scitation.org/doi/10.…
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πŸ‘€︎ u/Aerothermal
πŸ“…︎ Feb 08 2021
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Determining free variable for figuring out dimension space and span

Suppose I have a matrix that is v1 = [1, 0, 0]T v2 = 1, 0, 0]T v3 = [0, 1, 0]T v4 = [-2, -1, 0]T v5 [3, 1, 0] multiplied by a vector [x1, x2, x3, x4, x5] which equals to a zero vector [0, 0, 0]. How do I determine the free variables of the matrix? I can write it out into a system of equations but I am confused how to find the values of each x if that makes sense.

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πŸ‘€︎ u/pinketude
πŸ“…︎ Feb 25 2021
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I got tired of looking up Swift basics after forgetting the syntax, so I made Swiftly, a one-stop Swift 5.1 reference site for busy coders. With clutter-free, example-heavy guides, Swiftly covers everything from variables to in-depth areas like collection types, structs, and functional methods. swiftly.dev/
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πŸ‘€︎ u/eugeniu
πŸ“…︎ Oct 29 2019
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How do I find the lower bound of such function with 2 variables?

For n,m βˆˆβ„• find infimum of n|(n/( √2)) - m|. (It's lower than 1, Dirichlet's approximation theorem). I tried to take derivative of it in respect to n, but I'm not sure if it's even legal, and I might lose some of my answers. Any other methods?

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πŸ‘€︎ u/Kaajpl
πŸ“…︎ Oct 29 2018
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Experimenting with a bulk substrate recipe. 50/50 potting soil w/ vermiculite and black kow. Didn’t add coffee but I will next time just to add a variable to the test. 24hr progress let’s hope we stay contam free πŸ™πŸ½ reddit.com/gallery/j288gl
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πŸ‘€︎ u/YoursTruly7000
πŸ“…︎ Sep 29 2020
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Unable to use let-bound variables in defuns?

Have a small elisp problem. Even though everywhere I read on the internet says it's possible to use variables bound by let inside of a defun in the same let like this:

(let ((something 0))
  (defun some-random-function ()
    (interactive)
    (message something)))

Doing that gives me the some-random-function: Symbol's value as variable is void: something error, as if the variable is unbound/out of scope. Am I mistaken, did something change, etc?

I'm using GNUemacs Version 24.5.1, if that matters. Would love somebody to clue me in as to what's going on here.

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πŸ‘€︎ u/Gangsir
πŸ“…︎ Aug 06 2018
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Renaming Inspector Bound Variables Without Losing Data

After long debate, I decided to change my properties convention from camelCase to PascalCase to conform with the C# standard.

Before, I was prefixing any private variable that had a property with an underscore. Example:

[SerializeField]
private int _someValue;
public int someValue { get { return _someValue; } }

Over time, I disliked this practice more and more. So, I bit the bullet and started. One crucial thing I forgot is the data assigned via the inspector. In one instance, there were over well over 50 occurrences of an inspector bound variable with a specific colour code.

On renaming this serialized field, instantly the values were lost. I had to revert my project version in an attempt to recover what I had lost. At this point, I nearly gave up. I considered developing some sort of editor tool to store the original value, then rename my original variable, and port the value over--but it didn't seem worth it at this stage of the project.

However, just today I discovered the solution. You can rename inspector bound variables without losing their data by using the [FormelySerializedAs] attribute in the UnityEngine.Serialization namespace.

Here is the Unity post on its usage.

I just wanted to post this here incase anyone else has encountered, or is encountering this problem.

Thank you for reading!

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πŸ“…︎ Dec 15 2018
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Lambda Calculus question: Can a function definition have no bound variables? [Homework help]

"Provide an example of function definition with no bound variables and at least one free variable. Is it still function definition? Justify your answer."

My initial reaction is "no". You cannot have a function definition with no bound variables. How can you? If my function definition is "Lx.x y" then "x" is bound and "y" is free, so how could you possible define a function without a bound variable?

But I'm doubting myself because of the way the question is worded. He says "Provide and example", not "Can you provide and example"... Am I way off here?

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πŸ‘€︎ u/devil_d0c
πŸ“…︎ Oct 24 2017
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I got tired of looking up Swift basics after forgetting the syntax, so I made Swiftly, a one-stop Swift 5.1 reference site for busy coders. With clutter-free, example-heavy guides, Swiftly covers everything from variables to in-depth areas like collection types, structs, and functional methods. swiftly.dev/
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πŸ‘€︎ u/eugeniu
πŸ“…︎ Oct 29 2019
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how are y’all doing in apcsp cus I’m struggling. πŸ₯² my teacher doesn’t teach and just assigns us code.org I barely know how to use a variable and we’re on filtering lists 😭
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πŸ‘€︎ u/Lazystrange
πŸ“…︎ Dec 03 2021
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