Storing Universities in MySQL

Question: We are building our site and we are constantly adding new universities. I have a class that manages a lot of this. The question is, when people register, should we store the university they attend as the full string in the database, or convert each university to a unique int and store this, or create a new table of all the universities and just add them in manually as we add more schools to our system, then just store the primary_key of the chosen school in the users table? The easiest would be just to store the string. But I feel this may be inefficient.
Comment: The latter.  Definitely.
Answer: you should definitely create another table for universities and store PK of this table in another tables , so you can perform operations on these tables easier
Answer: I think storing the full string every time is very inefficient. I would tackle this by storing just the universityId number for each user, and then use SQL querys to retrieve whatever information you need.
This way you will avoid duplicity in your data (e.g.: Different users from the same university entering different strings)
Answer: I agree with the previous answers.  You definitely want to use a university id primary key, and not just a string with the university name!  Designing your database in this way is called normalization.  Take a look at this article, for an introduction to normalization including a bit of discussion on why you need it.

Storing Universities in MySQL


When should a user story be marked as "blocked" and not "To-do"

Question: In 1 sprint, we are having 2 user stories.
One is for design and one is for coding/development based on the design. We are having different statuses in Jira like
To-Do,
Blocked,
In Progress, etc.
Now, the developer is putting his development user story under "Blocked" as he is waiting for the designs. He is of the opinion that the story is blocked for him as there is nothing he can do until he gets the designs. The dependent story (for the UX designer) could either be in To-Do or In Progress.
Is this the right approach ? Should the developer put his story under To-Do or Blocked ?
Answer: I'd ask the team what benefits does they find from having two user stories for the same piece of functionality?
I advise teams not to split backlog items into stories for specific disciplines. In this case, I'd have one product backlog item (one user story) and let the team know that the backlog item is what they're agreeing to if they bring it into the sprint backlog.
In your situation (as I don't like changing approaches mid-sprint), can a developer be blocked on something they haven't started?
Could the developer get early visibility of the designs to understand things like content or data structure?
Are there aspects the developer can work on that they can finalize with the designs?
Questions like these encourage closer collaboration, and remind the team that it's the team that delivers, not individuals.
Answer: "Blocked" should never be a state in a workflow, which includes a status in a Jira workflow or a column on a board. Calling something "blocked" is a description of the work, but not a status. If something is blocked and To Do, that shows that it can't be started due to some condition. Similarly, if a unit of work is identified as blocked and its In Progress, that indicates that no more progress can be made on the work until something is resolved.
If you're using Jira, using a label or a flag on the issue is a better way of indicating that something is blocked. You can then highlight these issues on your board to make them visible and the team can work to resolve whatever issues are preventing progress.
The problems that you are facing are much more fundamental than being able to identify blocked work, though. It seems like you are trying to start development before the necessary preconditions have been satisfied. There are a few ways to handle this. One would be to have a more complex workflow and use a single issue to track it through the ideation, design, and refinement process before development. Another solution could be to make sure that the necessary design and refinement is done before development so the work doesn't get blocked. There may be other options, too, but I'd say that there are deeper issues if you're regularly having development work blocked because prerequisites aren't met.
Answer: "Blocked" is normally reserved as a state when the team as a whole cannot progress the item. So in this case, I would not consider it "blocked", because the team can do meaningful work to finish this story.
In the specific case of this ticket waiting for the design decision in another ticket, you have two choices: you can either (a) not put the ticket into the sprint until design decisions are made and done the previous sprint, or (b) make design decisions a task under the story, just like implementing, code review and testing are (or should be). But having a story in the sprint that cannot be worked on until another story is done is not really good. User stories should be independent. And bring value to the user. In this case, they are neither independent, nor does finishing just one bring any value. The user won't notice if you already have the design done. The button is still not there, even if you made a sketch of how it would look if it were.
Either way, saying it is "blocked" is a little strange, because if you view it that way, it has been blocked since the sprint started.
In the end, there is no law governing tags in your workflow system. You can name it and tag it with whatever you want. But for the teams I have been part of, "blocked" always meant that we as a team cannot progress this item and we need outside help or input.
Bring it up in the retrospective. See what your team thinks and how they want to handle it. Having dependencies between stories is never good, but I don't know your team structure or workflow enough to make any real suggestions here.
Answer:
He is of the opinion that the story is blocked for him as there is nothing he can do until he gets the designs.

The reality is that without any design and refinement, the entire sprint is blocked, so your designer is correct in a lot of ways! What you need to ensure is that you ensure any refinement and design is completed before development commences and that might include design decisions as a ticket.
You need to emphasise to this designer that you are all part of a team and that blocked is to be used realty when the team cannot move forward.

2 user stories. One is for design and one is for coding/development based on the design

I'd be interested to hear more about this
Answer: A blocked task must contain a reason why it is blocked and someone else from the team, or external to it, must be assigned to unblock the task. The person assigned by someone else might not have the answer, so further assigning people until finding the answer.
Outside the process, a meeting can unblock a task also.
If the task is blocked due to dependency conflicts, I would highlight this as a bad prioritization by the product owner as this should be discussed with devs and taken into account by him/her during the sprint planning.
I bet the above-mentioned issue is the root cause of the problem!
Imagine the PO wants a new frontend that will require designs, but they start a sprint with no designs... the entire team will look at each other while designs are getting done... crazy!
Answer: This is interesting.
My opinion is user stories are meant to be independent and assuming two user stories for a sprint does not seem right with me.
Create one user storie for it and in your worklow you can have blocked there so as to be an indication to the team that the design has to be done in time.
Blocked in the workflow is a good thing but it shouldn't be mixed with product backlogs.


Set first letter of paragraph to different color in InDesign

Question: In my document I want to color the first letter in my paragraph (among other things). I already found out how to set the first letter as initial, but now I also want to change its color based on the template used for the paragraph. Is that possible?
Comment: Does the below answer your question?
Comment: @Darth_Vader: Will test tomorrow, I have no access to InDesign from my home computer...
Answer: This can be done by setting the first letter as a character style.  I call mine drop_cap:

After applying the character style you can open the style and go to Character Color to change it:

I think you should read up on character and paragraph styles, from Adobe: "Paragraph and character styles".
Comment: You would have to manually apply this to each character though, right?  Is there a way to automate it?  It seems to me that's what OP was asking about...maybe I misinterpreted it.
Comment: I didnt see that from the OP or I would've made the edit for the tag.  I do imagine that you could do it through scripting.
Comment: They said "but now I also want to change its color based on the template used for the paragraph" so I took that to mean automatically, but maybe I'm wrong.
Comment: well if the document was built correctly and styled correctly one edit to the style itself should effect everything applied to that.
Comment: Decided to post my own answer, to show what I meant haha
Comment: I think the approach from John Manly is more suited for me, but it will be tested tomorrow.
Answer: I'm going to take a slightly different approach to solving this.  While he is definitely not wrong, Darth's method will involve you having to apply your style to each character manually—a process that could be very time consuming on a large document.
I'll show you how to do it automatically.

Open your Paragraph Style Options and go to the Drop Caps and Nested Styles tab
Click on New Nested Style

Click on the section that says Word and select Characters from the drop down

Click where it says [None] and select New Character Style...
Choose whatever style settings you would like the first character of each paragraph to have and click Ok.  In this case, I chose to have the first character of each paragraph be displayed in Impact font, 18pt, Magenta.

The final result:

Every paragraph with this style will have the uniquely styled first letter.  To change the styles, you can simply edit your newly created Character Style
Comment: Hmm, my first letter still is black, not magenta, even if I added the nested char style...
Comment: @arc_lupus maybe make sure you don't have any style overrides enabled?  You can disable them by clicking [this button](http://i.imgur.com/anRouvC.png).  Otherwise, I'm not sure why it's not working for you.  I'd have to see it for myself.
Comment: Where exactly can I find that button?
Comment: @arc_lupus http://i.imgur.com/oDxzkPd.png


Cross validation techniques

Question: What are the advantages vs disadvantages of cross validation types? Like k-fold, leave one out, etc.
Comment: LOOCV may not work well for a data set with many samples. In the case, you would need to increase the amount you leave out
Comment: @GK89  why wont it work well?
Answer: As you probably know by now, cross-validation is a method of:

partition dataset into 'train set' and 'test set'
fit model to train set, get the prediction error on test
repeat (1-2) in a bunch of different, 'pre-defined' ways, storing the prediction error each time.
average all the prediction errors to understand how your model will behave in the wild!

All the 'magic' of different cross-validation (CV) types happens at (3), basically. Say your dataset has $n$ observations.

leave $p$ out CV separates your dataset into a train set of size $n-p$ and a test of $p$, gets the prediction error, and repeats this process for every single possible $p$-sized subset of the dataset.
leave $1$ out CV is a special case of leave $p$ out where $p=1$
$k$-fold cross CV partitions your dataset into $k$ equal sized partitions, trains on the first $k-1$ partitions and tests on the last partition, and gets the prediction error. The result at the end is ten $k$ prediction errors to average over. (Note that $k=n$ is the same as leave $1$ out CV.)

As for disadvantages and advantages, it's basically just a trade-off between exhaustiveness and speed. And I guess it depends on your dataset. The upper limit of exhaustiveness is basically doing leave $p$ out CV for all $p=\{1,2,...,n\}$. Probably depends too on the linearity of your dataset. In my experience, I haven't had trouble using $k$-fold cross CV.
Reference

Cross validation techniques


Retrieve previous version (backup file) of Excel file?

Question: I made some incorrect changes and clicked 'Save' in MS Excel. 'Undo' failed.
Excel does not have an option to create backup files, like MS Word does.
The AutoRecover option saves files in C:\Users\Jan Doggen\AppData\Roaming\Microsoft\Excel\ and I found an Excel11.xlb file in that folder, but it turns out that is only a settings file.
I know of two options that I have:

Use recovery tools (ASAP) to scan erased file space for an Excel file with the same name, and hope these retrieve something useful - not likely I think, because a few incorrect bytes in an Excel make it unreadable.
Go back to an older version I have in a backup. Luckily I do.

Are there maybe more options that I overlook?
I scanned my C: partition for file names that could indicate previous versions, but I found none.
Answer: The Undo feature still works after saving as long as you did not close the workbook. You could also turn on Track Changes before hand and you would have a history of that.
Comment: Undo failed, alas (sorry, should've mentioned that). Didn't know about 'Track changes', I'll look it up.


Are there animes/mangas we want more questions for?

Question: I've been looking at the tags and I was looking at some of the chat from yesterday and saw that we have a really skewed number of questions. Are there some shows/manga that we want to attract/generate more questions for? And is there a good way to do that?
Comment: We aren't necessarily looking for a specific series, just a more diverse range of series.
Answer: Yes this is indeed a huge issue right now as the site right now is mostly dominated by Naruto.
There is a significant lack of representation for the Type B fan genre. (Namely those who watch fansubs/raws and new shows.)
For example, Madoka is one of the most popular shows in this genre. And yet we have only 3 questions in that tag compared to over 70 for Naruto.

LoganM and I are compiling a list of Anime in this genre and are actively seeding questions from that list. (some of which we probably already know the answers to)
Here's the list that I dumped in chat - just to give an idea of what kind of shows we need more of.As of yesterday, there were no questions in any of these shows. (there are now since I've seeded a few)
<code>Angel Beats!
Accel World
Baka to Test to Shoukanjuu
Black Lagoon
Fractale
Ga-Rei Zero
Guilty Crown
Gunslinger Girl
Hanasaku Iroha
Hyouka
Kami nomi zo Shiru Sekai
K-On!
Kannagi
Macross Frontier
Mahou Shoujo Lyrical Nanoha
Ore no Imouto ga Konnani Kawaii Wake ga Nai
Shakugan no Shana
Tari Tari
Tasogare Otome x Amnesia
The iDOLM@STER
Tiger & Bunny
Toaru Kagaku no Railgun
Toaru Majutsu no Index
Zero no Tsukaima
</code>
Since I only watch shows in this Type B (fansub/new shows) category, I'm actually running down my own MAL list and asking every decent question I can think of - regardless of whether I know the answer or not.
Basically, we're trying to get the volume up in this genre as much as possible as they will be needed to attract this audience.
Answer: Mystical's answer is good. Some of those now have one or more questions from the past 24 hours. However, it is ultimately missing some things as well.
I don't think it's an issue of particular shows. We want more questions for all shows. But we also have an interest in keeping genres balanced so that all users can freely ask and answer questions about the shows that interest them. Right now that is the case for Naruto, Bleach, One Piece, and a handfull of other action/shounen shows. But there aren't many questions from other genres. That makes it hard for new users to contribute, and it's a bit off-putting if you only see one genre on the main page unless you are a fan of that genre. If we went viral right now, we'd be a hit in the Naruto community, but we'd have trouble bringing anyone else in, which would only make the problem worse. What we want is balance, so that we can attract a wide range of users whose interests span all of anime and manga.
The solution is definitely not to lower the number of shounen questions. That would require us to stop people from using the site the way they are supposed to be. We should strive to be a good resource for all genres, and we're already doing that for shounen. Now we need to expand to other genres. The list we put together is a good place to start, but if we stop there we will have just become a reference for those shows. It's got almost no shoujo or jousei works, which is a pretty big problem. It also has no sports shows, and we've had very few sports questions so far. Mecha is also underrepresented on the main site and on the list. And finally that list is tilted heavily towards newer anime. There may be more issues that I have not identified as well.
So what can you do?
First, if you're primarily interested in shounen, keep doing what you're doing. We need a continued supply of good questions and answers in order to keep people visiting the site. You might also consider checking out some other series from different genres if you see one that looks interesting on the main site, but you aren't obligated to do that.
If you're interested in other genres, you should ask questions about shows in those genres. It's fine to ask even if you know the answer. In fact, you can even answer the question yourself if you know the answer. You might want to keep the question open for a little while before you do, because it could bring in answers from other interested people. The list on Mystical's answer is a good place to get started if you can't think of anything. Make sure they're good questions, though. You shouldn't ask a question just for the sake of putting it on the main page; it should be something that someone might want to know in the future. This is called seeding, and it's encouraged on beta sites.
Also, don't spam new questions just for this purpose. This may seem contradictory to the above, but it really isn't. We want to maintain balance, and if one user asks a lot of questions in a short period of time, that isn't maintaining balance. Instead of that, save that third or fourth question for another day. Right now the main page is actually very diverse, so there isn't too much need for new questions unless it fills some hole. If, in 48 hours, the main page has a lot of shounen questions, that's the right time to post some more.
If you see a question that seems like low-hanging fruit that was posted for the purpose of seeding, you should ask yourself if you really need the reputation for answering it. Sure, you can provide a good answer, but so can a new user who is looking to get started on the site. Part of the purpose of asking these questions is to increase the accessibility of the site to those who aren't knowledgeable about shounen specifically, and giving them some easier questions doesn't hurt that. If you're having trouble building up rep because the shows on the main site aren't diverse enough, then you should definitely answer, because you're the people who are supposed to benefit from it the most. If the question goes for a while with no answers, then anyone should feel free to answer it, but as long as it's on the main page, people are still looking at it. For this reason, I don't intend to answer any of these questions unless they clearly aren't going to be answered any time soon, and I'd recommend that other high rep users do the same.
Finally, don't forget to upvote questions you find interesting. This is especially important for the seeding questions, because it's just not as fun asking and answering questions when you only get +5 or +10 per question. These questions won't survive if we don't keep upvoting the interesting ones.
For now, Mystical and I are mostly dedicated to this, and a few other users like Krazer are helping. Anyone else is welcome to help. I don't think there's an immediate need for more questions from anime like the ones Mystical listed right now; instead, we should let the first wave gradually be answered and keep adding a few more whenever the balance gets worse. However, we're still lacking in other genres, particularly shoujo and jousei, so those should be a high priority. Right now, we've actually had the opposite effect: Naruto is pushed all the way to the 28th question. So we should hold off from the list shows for a little while and let the site reach a more stable balance before we add more. I have no doubt that in a day or two we'll need some more to rebalance the site.
Comment: Much better put than what I've said.
Comment: And as for the problem of getting shoujo and josei genres. I believe the problem right now is that we don't actually have anybody active here who watches those genres. So that might be tricky to get the ball rolling.
Comment: @Mysticial The OP seems to have some knowledge of at least a couple of shoujo shows. Krazer has some answers about shoujo. I can wing a few questions from Kimi ni Todoke, Shugo Chara, Maid-sama, Honey and Clover, Kuragehime, Usagi Drop, etc. So while I agree that it will be harder, it's worth doing. Of course, the problem might work itself out on its own once we bring in more people interested in e.g. romance shows, but it also could keep getting worse if we do nothing.
Comment: I've only seen Skip Beat and Kare Kano - ages ago. I can try to squeeze a question out of them. We'll see.
Comment: I think it'd help to put "shoujo" in the name of the question and/or in the body so shoujo fans can find it by searching. I've searched for "shoujo" to try to answer more questions but I don't have time to type in every shoujo series title just to check if there happens to be a question for it. I've just done a search of the titles you mentioned here in these comments and it looks like nobody did end up squeezing out a question about any of them, so they're not searchable for a shoujo fan to find and want to become active in the site in order to answer them.
Answer: The more useful point, rather than what series would we like more questions for, is how to attract the sort of people to get invoved in the site who know the answers to questions about other series and genres.
Mysticial's list above was comprised of then-airing series, which I watch, but conspicuously did not contain a single shoujo, josei, children's, etc. series to generate more diversity of content (as noted in comments above). However, the problem with simply having people like me (who are quite knowledgeable about pretty much all shoujo series from the 1970s to the present) ask more questions is not going to fix the lack of questions, because what is needed is more people who can answer the questions.
I have asked a number of questions (such as 1, 2, 3, 4) which are not about extreme minutia or obscure series, but when no one is able to answer them and no one is interested in them enough to even upvote them, my reputation suffers because these questions did not generate enough response from others (I've certainly earned the Tumbleweed badge). If people can't answer simple questions about Sailor Moon, I can imagine the lack of response I would get if I asked a question about classic shoujo anime such as Mahou no Mako-chan or Seine no Hoshi or even something contemporary such as Chihayafuru. So to keep my reputation up and my time not wasted, I practically need to ask questions that either 1) I can expect someone already knows the answer to or 2) someone can Google search to find the answer for me, and I need to at the same time avoid posting questions that 1) I imagine not many people here already know the answer to and 2) cannot be easily found by web search but would instead require the answerer to have actually watched the show in order to know the answer.  In other words, if my asking questions about a popular series is met with few views, only 0 or 1 or 2 upvotes, and no answers, I'm not motivated to ask more of the same nor to ask more niche questions than those. If someone else is attracted to the site who is knowledgeable in the genre, then I would become more motivated to post more questions, and the number of questions and answers would both increase.
Answer: I am not sure that is such a bad thing. As a whole, this site's population represents the demographics of the real world anime/manga fans. That means, there are more naruto questions here because more people follow it. In other words, if you randomly pick an anime/manga fan, he/she is more likely to be following Naruto. That's not easy to change.
Any artificial means to "correct" the demographics would be futile for now. Let's say, I feel like I should correct it, and start watching some relatively rare anime. Then I ask questions, but what's this? No one answers, because no one else watches them! The other alternative is answer my own question, but what purpose does it serve, if no one else finds it useful?
However, I am not entirely pessimistic on this. As more people join, we would hopefully have more "non-Naruto" fans (here, I use Naruto to represent the other popular series as well), and then we would hopefully get more questions on other anime too. However, the distribution will always be skewed in favour of Naruto and other popular anime.
Comment: Also, if by "obscure anime", you mean the sorts of things Mystical listed, then I don't think they're that obscure. We have quite a few users interested in these shows. If you mean [tag:parappa-the-rapper], then I'll admit that it's pretty obscure and unlikely to help anyone in the near future.
Comment: It's not so much the fact that Naruto is the most popular that's the problem; it's that it is dominating to the point that it's turning away fans of other types of shows who don't watch Naruto. If I go to http://myanimelist.net/topanime.php?type=bypopularity, Naruto is indeed quite popular, but only #4 on that site (which may not be entirely representative, but it's a good guess). Bakemonogatari has 60% as many viewers, but 0 questions vs 67. AniDB has very similar statistics. Even if these are skewed and it only has 10% the viewership of Naruto we're still overdue for some questions about it.
Comment: I get it now. Let me think about it.


what is wideband phase shifter in modulator?

Question: in these days I have been studying communication systems.

and I want to know the role of wideband phase shifter in the picture above.
Answer: See Wikipedia for the mathematical formulation of Single Sideband: it is a special case of quadrature modulation, in which the quadrature signal is derived directly from the in-phase signal by a 90-degree phase shift. The Wideband Phase Shifter in your diagram produces the Q signal from the I signal (taken as the input).
Your diagram was traditionally known as the Phasing Method of SSB generation (in contrast to the Filter Method). It is difficult to accomplish an accurate 90-degree phase shift over a wide band (even a typical audio bandwidth) with passive components, which is why the Filter Method has dominated SSB generation until recently. Modern DSPs implement a Hilbert transform to accomplish the phase shift, dramatically reducing the cost, size, weight and power consumption of an SSB generator.
Answer: This is a single sideband modulator.
The message signal m(t) is assumed complex. It may be the output of a baseband QPSK modulator for instance. The wideband phase shifter takes each frequency component in that signal and supplies it 90 degrees out of phase to the two product modulators (aka multipliers). Together with the 90 degree phase shift of the carrier signal fc, this means that when the two products are recombined in the adder, m(t) will have been single sideband modulated onto fc.
In slightly more mathy terms, for each frequency fm in the message, the output will contain a frequency of fc+fm, or fc-fm (depending on the polarity of the modulators), but not both.
Bear in mind that as m(t) is complex, it has both positive and negative frequencies, thus the need to continue to keep them apart when modulated up on the carrier.
If terms like QPSK, baseband, the concept of negative frequency or a complex signal are puzzling to you, you will need to do a lot of background reading. This answer space is too small for a complete signal processing and communications course.
Comment: so I understand you mean the wideband phase-shifter places M(f) far away like M(f-fa), so not to make interference with m(t)*cos(2pifct). Am I right?
Comment: No, not even close. M(f-fa) is a frequency shift, not a phase shift. I'm looking through wikipedia trying to find a good article, and it doesn't have any, at none that are easy to find. I'm appalled. If I find one, I'll post a link here. If I don't, I might feel compelled to write one. I'm sure there's stuff outside wikipedia, the DSP manufacturers must have some app notes. Watch this space.
Comment: Have a crack at [this](http://www.ece.umd.edu/~tretter/commlab/c6713slides/ch7.pdf). It's not great, but it is accurate. Fig 2 shows your diagram, but there's little exposition.
Comment: No, I've come up short trying to find anything reasonably educational out there, I'm going to quit, but I'll bear you in mind and if I stumble across something, I'll come back and link to it. How did I learn? I don't remember, it feels like I've always known it. I sympathise with your plight. Try your local library for text books on digital comms. Try the various analog.com, ti.com etc for tutorials
Comment: oh thx a lot. I'm really appreciate about your comment. I'll keep in it in mind


How to send correct SwapExactEthForTokens params types on ethers/web3.js?

Question: I need to know how to send correct paramaters / paramater types as in what does the parameter type has to be is it a hex number , a string ?
help would be massively appreciated.
Notes:
1)i cant set value in trade (object sent with value and gasPrice) to 1 bnb in wei i get an error that its a bignumber.
2)sometimes the code actually works and i get a hashcode but this hashcode doesnt yield any information of an existing transaction at all.
I imported pancake swaps router functions like this :
const router = new ethers.Contract('0x10ED43C718714eb63d5aA57B78B54704E256024E', [
'function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
 external virtual override payable returns (uint[] memory amounts)',
'function getAmountsOut(uint amountIn, address[] memory path) public view virtual override returns
(uint[] memory amounts)'], account);

Then I proceeded to use these functions to pull a trade with the following code :
const init = async () => {
desiredCoin = '0x0231f91e02DebD20345Ae8AB7D71A41f8E140cE7';
bnb = '0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c';
const pairAddress = [bnb, desiredCoin];
//use https://bscscan.com/unitconverter to input bnb amount.
const amountIn = 1
amounts = await router.getAmountsOut(
    amountIn,
    pairAddress
);
amountOutMin = amounts[1].sub(amounts[1].div(slippage)); //slipapge set here
console.log('Calculated Amounts out: ' + amountOutMin);
const to = bnbwalletAdress;
const deadline = Math.floor(Date.now() / 1000) + 60 * 10; //this represents 10 mins of deadline, change to ur liking.
const tx = await router.swapExactETHForTokens(
    amountOutMin,
    pairAddress,
    to,
    deadline,
    {value: 1, gasPrice: 10e9}
)
console.log('Transaction Submitted, heres the hashcode '+ tx.hash)
receipt = await tx.wait();
console.log(receipt);
}

Answer: Answer for Q1
If not specified, usually the value is in "wei".
So "1 ether" would be 1000000000000000000 wei.
You can use web3.utils to convert "ether"->"wei". web3.utils.toWei('0.01', 'ether')


Why methyl group is 2,4-directing?

Question: Why methyl group is 2,4-directing? I am an A level student and this isn't required at this level. I am looking for a simple explanation which a high school student can understand.
Comment: Do you understand the rationale for other directing groups?
Comment: To solve this problem, draw the intermediates of reaction.  It will be obvious at that point-- or otherwise for the basis for a useful discussion.
Answer:
Why methyl group is 2,4-directing?

When toluene undergoes electrophilic aromatic substitution the products are primarily the ortho and para isomers; usually only a small amount of the meta isomer is produced.  In order to explain this observation there are two effects to consider, inductive and resonance effects.
Inductively the methyl group releases electron density into the benzene ring.  This is because the methyl group, being $\ce{sp^3}$ hybridized, is less electronegative than the $\ce{sp^2}$ hybridized aromatic carbon.  The carbon with more s-character is more electronegative, electron density likes to flow from low to high s-character orbitals since the more s-character in an orbital, the lower its energy.  If inductive arguments were most important we would expect the ortho isomer to predominate followed by the meta and para isomers in that order.  This is not observed, the meta isomer is only a minor isomer.
Resonance arguments are based on the concept of hyperconjugation involving the $\ce{C-H}$ bonds in the methyl group.  The following figure shows some of the possible hyperconjugative resonance structures for toluene.

Additional resonance structures can be drawn using the other methyl $\ce{C-H}$ bonds as well.  As the resonance structures show, electron density is increased at the ortho and para positions, not the meta.  This hyperconjugative resonance effect makes the ortho and para carbons more susceptible to electrophilic attack.
Hyperconjugation explains how alkyl groups can be electron releasing in a resonance sense.  Hyperconjugation explains the mild activating effect of an alkyl group in electrophilic aromatic substitution and its ortho-para directing effect.
Comment: @Lighthart Why should the argument be more or less convincing if we apply it (hyperconjugation) from the starting material or the intermediate side?  Hyperconjugation is applied to other neutralmolecule phenomenon like the rotational barrier in ethane and why more highly substituted alkenes are more stable.
Comment: Hyperconjugation is too quantum mechanicky for mere mortals to grasp easily.  I have found students grasp the energy of the resulting cation intermediate more quickly.  So the people I am convincing more easily are novices.  Your explanation is quite good, but very sophisticated.
Comment: @An_Elephant  What you say is correct, but what I've drawn is just a resonance structure.  It is an extreme form with charge separation, but it is meant to indicate that the $\ce{C-H}$ bond donates electron density into the ring (e.g. hyperconjugation).
Comment: I find this argument is a lot more convincing when applied to the EAS intermediate, not the putative hyperconjugated-dissociated zwitterion.
Comment: @ron But I learnt that hyperconjugation occurs when there is partial overlap of C-H sigma bond and adjacent empty-p orbital of carbon. However your structures suggests to contradicts this as the C-H bond is fully broken, C=C bond is completely formed and a unit positive charge is involved in the resonance?
Comment: @ron Is it better to say that only partial electrons and partial positive charges are involved in the structures, assuming electron wave nature instead of particle nature?

Why methyl group is 2,4-directing?


Single profile vs multiple profiles

Question: Is it against SE rules or suggested good practice to have a different profiles for every SE site rather than a single  profile?
Comment: [Duplicate](https://www.google.com/search?q=site%3Ameta.stackexchange.com+are+multiple+accounts+allowed) of [What's the policy about having multiple user accounts?](https://meta.stackexchange.com/questions/35593/whats-the-policy-about-having-multiple-user-accounts).
Comment: OK then yes, in general, you can do that but be aware of the consequences so you don't accidentally trip the vote fraud detection. Nothing is stopping you from having as many profiles as you like, on any site.
Comment: Jeff answers this in the dupe: "It is not a problem to have multiple accounts, as long as they aren't voting for each other and doing other sockpuppet-y things." This has not changed over time, as far as I can tell.
Comment: Can I ask why you would want this? Network profile is very convenient and as an answer states, will get association bonuses. I understand why someone may want multiple log ins on a single site, I can't see any reason to mange seperate emails and passwords etc for each site you join.
Comment: Do you mean different profile texts or actual separate accounts?
Answer: Managing more than one login is a utter and complete pain (and I have a second account for a reason, and I only use it at work), and there's no real benefit from it.
Having one per site means separate emails and passwords per site
If you have a separate account per site, in theory, they won't interact with each other but there's a reason we have a single sign on across the network.
This might also lead to some weirdness if you do accidentally create a second account on a site you do already have another account on, especially if you manage to trigger off an automatic account merge.  (It shouldn't happen.) You would also run afowl the rules if you're suspended somewhere and accidentally interact on another account.
Save yourself the pain and make use of the mostly excellent single sign on across the network.
Comment: You didn't really answer the actual question here though. The question is if it's against the rules.
Comment: Well, its not best practice. The dupe covers the rest :D
Comment: @JourneymanGeek - no, the dupe has little to do with my question as well as your answer. Anyway thanks for your effort,
Answer: Yes, if you want to have separate profiles per site you can do it that way if you really really want to since those profiles won't be able to interact with each other, but there are significant advantages to having a single profile.

You can benefit from the association bonus on all sites. This means, amongst other things that you start out being able to comment on any site you join.

You also see all messages in one place e.g. if someone comments on one of your posts, you'll see that message regardless of which site that comment is posted on. Otherwise you'd have to log in separately to each site to see if anyone's asked you for clarification or in fact solved your problem.

You can always hide your profile on some sites so it's difficult for casual viewers to see that you're active on particular sites if you're worried about your privacy.
Comment: @Gio https://meta.stackexchange.com/questions/290092/how-do-i-hide-my-accounts-on-a-specific-stack-exchange-site

Single profile vs multiple profiles


Review of sprint board during the sprint session?

Question: What is the name of the session that the scrum master and PO during the sprint review the sprint board to see and the progress, update the status of the tickets and sometimes include some team members for this?
In some cases I have heard it as grooming meeting, but usually grooming is the refinement before sprint planning.
Comment: "The sprint board" isn't something that Scrum requires.  Therefore, Scrum cannot have an event that needs it.  The Team can choose whatever means they find helpful to coordinate work and make progress visible.  Communication with PO and SM is also up to the team to determine, though I would expect the latter to regularly attend the Daily Stand-Up.
Answer: Such an event does not exist in Scrum. In Scrum, the Sprint Backlog is "a plan by and for the Developers". The Developers are expected to choose a mechanism (which may or may not be a board) to give stakeholders a "visible, real-time picture of the work" that is being done over the course of the Sprint to accomplish the Sprint Goal. The Developers should be the one updating their Sprint Backlog to give the Product Owner visibility into the status of their work.
Answer: This touches on the roles & responsibilities of the scrum team:

Product Owner is responsible for the management of the Product backlog
Developers are responsible for creating the Sprint plan (Sprint Backlog) as well as adapting their plan each day toward the Sprint Goal;

If you are looking for a status updates mid-sprint, it sounds like there may be a transparency and inspection breakdown (two of the cornerstones of Scrum theory). Questions to bring back to the team:

Is the current project tracking tool (e.g. Board) a good fit for the team? Are the developers able to easily keep it up to date?  Does the Product Owner have access? Is the information being documented of value?
If the tool is a good fit for the team, what barriers are stopping the developers from updating? For example, is the daily scrum (or other meetings) being perceived as status update and therefore no need for update in the Sprint board implying a reliance upon the Scrum Master as participate for Product Owner update?

If you get to the root cause of why your transparency issues exist, then your inspection issue may no longer be a problem.
In terms of the other ceremonies mentioned, depending who you talk to sprint planning, sprint grooming, and sprint refinement may be perceived as exchangeable concepts or distinct. "Sprint planning" is the term referenced in Scrum.
Sprint planning: Often composed of at least three parts: Why does this work matter? What work is available? How will it be accomplished? Takes place at the beginning of the sprint.
Sprint Review: Take place at the end of sprints and is an opportunity for the team to inspect outcome of the sprint, gather actionable feedback, and discuss the future. Participation is often inclusive including Developer team, Scrum Master, Product Owner, stakeholders.
Common agenda items:

Overview of what was "Done" and what has not been "Done";
What went well, problems, mitigations;
Demonstration of work that is "Done" and answers questions;
Product Owner overviews current product backlog, and projects targets/delivery dates


How do I get pictures from a Nikon Coolpix p520 to a Linux system?

Question: I have a Nikon Coolpix p520 and just got a computer with Linux Lite. Is there a software for Linux computers so I can get my pics and video on my computer?
Answer: This camera is supported in PTP mode (that is, plug it in via USB and transfer images) by gPhoto, which is a library used by many applications, including DigiKam, Shotwell, and more. In fact, because this library is very common, I'd expect most programs for photo management in Linux to just work.
However, many people find it most convenient to remove the SD Card (memory card) from the camera, and put it into a reader. This is often faster and less finicky, and card readers (whether USB or built into a laptop) are almost universally Linux compatible (I can't remember the last time I found one with issues — more than a decade ago).
This camera doesn't have RAW support, so the files it produces are all in JPEG format. Many different editing tools support JPEG files, so this should be no worry.


Why would I put an ASI into Con instead of taking the Tough feat?

Question: I know that raising your Constitution modifier increases your maximum health. However, the Tough feat also does this, but gives twice as much health. What other benefits does a +2 to Con give, and when does that make it a better choice?
Answer: Constitution is not only good for hit points
You will have to weigh how important all of the following are for your character, compared to the 1 extra maximum hit point per level.
The PHB points out several uses for Constitution (p. 177):

The DM might call for a Constitution check when you
try to accomplish tasks like the following:

Hold your breath
March or labor for hours without rest
Go without sleep
Survive without food or water
Quaff an entire stein of ale in one go

Some of these, like starvation, tiring or suffocation, can have severe mechanical impact as they cause exhaustion, which can outright kill you, no matter how many hit points you have. A higher stat bonus will also improve your Constitution saving throw, which is important for

Resisting spells with constitution saves like shatter, flesh to stone, or finger of death
Resisting the effects of poison or disease
Resisting other harmful effects such as a monk's stunning strike
Resisting suffocation and starvation
Being able to keep up forced marches
Maintaining Concentration on a spell when damaged

Especially for spellcasters, the last one can make a big difference in a fight, for example if you polymorphed an extremely dangerous opponent into a frog, or are flying with the fly spell at high altitudes.
Several mechanics reward higher Constitution beyond just the saves. For example,

Starvation: you can go 3 + your Constitution modifier days without sustenance before you have to start rolling saves for exhaustion

Suffocation: you can hold your breath for 1 + your Constitution modifier minutes before suffocating, and then can only survive for a number of rounds equal to your Constitution modifier (minimum 1), before dropping to 0 hits and dying

Regaining hits: When you roll hit dice to regain hit points, you add your Constitution modifier to those rolls

Recuperating in downtime: you can make a Constitution check to end one effect on you that prevents you from regaining hit points, or to, for the next 24 hours, gain advantage on saving throws against one disease or poison affecting you

Chases, a DM option, where you are only allowed to dash Constitution bonus +3 times before needing to make Constitution checks or take exhaustion (Thanks, @AnnaAG!)

As a barbarian, you get to add your Constitution to your AC, if you don't wear armor, and from level 11 on, can make a Con save to drop to 1 hit instead of 0 in rage

For Dragonborn, the Constitution modifier counts towards the saving throw DC for their breath weapon

Champion fighters from 18th level regain 5 + their Constitution modifier hit points at the start of each turn if they have less then half their hit points left

Outside of the core rules

Going without sleep in the form of long rests without exhaustion (XGtE)
Pit Fighting to earn money (XGtE)
Beast barbarians level 10 Infectious Fury uses Constitution for its saving throw, their Call of the Hunt provides benefits like temp HP based on allies up to the number of your Constitution bonus,
Wild Magic barbarians use Constitution for the saving throws their Wild Surges cause
Rune Knight fighters use Constitution for the saving throws against their rune effects (Thank you, @ObliviousSage)
Cavalier fighters can use Warding Maneuver Con bonus times (minimum 1) per long rest
Comment: The 2 to highlight for me are concentration checks and hit dice. When rolling hit dice you can effectively get a second hit point out of each that you get for increasing con, so on a day you roll all your hit dice that point of con gave you the same overall benefit as tough, plus all the other goodies. Tough just front loads it, and also increases the healer tax.
Comment: Nice comprehensive answer, +1. I'd also add chase sequences, the number of times you can dash in a chase is directly limited by your Constitution, after you use them up you need to make Con checks for exhaustion.
Comment: Thank you. This is the comprehensive answer I was looking for.
Comment: I'll take the thanks, but it wasn't me that mentioned Rune Knight =D  ('Twas Oblivious Sage, rather.)
Comment: @nitsua60 Oops, fixed. Apologies for the mixup, ObliviousSage!
Answer: HP are just one thing that Constitution affects
You are correct that your Constitution affects hp, and that the Tough feat affects your hp twice as much as raising your Constitution modifier does.  However, your hp are not the only thing that is affected by your Con mod.  So there is the tradeoff between ASI and feat - do you want a smaller increase for many things in general, or do you want a larger increase for one thing in particular?
As MannerPots says, your Con mod also affects your Con saves.  Constitution apparently is the second-most targeted ability for spells that permit a save and far-and-away the most common ability for monster effects that permit a save (because so many monsters have poison).  And as MannerPots says, Con saves are particular relevant to casters for maintaining concentration.  They are also called for when you make a forced march, go without water, attempt downtime recuperation, or use a barbarian's relentless rage.
The Hobgoblin reminds us that if you are a Dragonborn, your Con mod affects the strength (DC) of your breath weapon.
Your Con mod also affects your Con checks.  The PHB gives some examples of these as when you might "try to accomplish tasks like the following: Hold your breath, March or labor for hours without rest, Go without sleep, Survive without food or water, Quaff an entire stein of ale in one go"1 (and, as AnnaAG adds, the DMG also asks for Con checks in Chases).  So you know, you might be Tough enough to take more damage, but can you drink alcohol really fast?
Your Con mod might affect other things like a Barbarian's Unarmored defense, a Champion's Survival feature, how long you can last without suffocating, and the Durable Feat.

1 Although this list is a little strange in that except for the ale-quaffing, each of those other cases is covered elsewhere in the rules by Con saves or a flat comparison of Con mod, not Con checks.
Comment: A little additional info, Though feat is strictly better if you already maxed Con or have a magic item that sets Con to a specific value that you are not expecting to surpass anyway.
Comment: @Mołot it's also strictly better if you have an odd Con score and only plan to use one ASI on it.
Comment: @Mołot I had considered that - but the question is why would someone take the ASI _instead of_ the Feat.  Having bumped up against a Con max is the opposite - a reason to take the Feat.
Comment: @Kirt I had the same thought about the Check vs Save thing. A little inconsistent. Given that the rules for saves are explict and specific, I'd go with saves in the cases covered by both.
Comment: @NobodytheHobgoblin I found it odd enough that I started to write a question asking about it, but on review was alerted to [this question](https://rpg.stackexchange.com/q/98698/23547) which was similar enough that I took some more time to think about it and then wrote an answer to that.
Answer: Improving your Con by 2 also gives you +1 to constitution saving throws. These are commonly used to resist many spells, as well as diseases, poisons, and conditions imparted by some monster attacks.
This is even more relevant for spellcasters since concentration checks (saves made to maintain concentration on a spell after taking damage) are a type of constitution saving throw.


Is there a specific name for an airport gate at ground level?

Question: At a two level airport most gates are located on the upper level with loading bridges or jetways. Is there a specific name for gates located on the lower level (ground) for like use of turbo prop airliners or small jets that do not use a jetway?
Comment: Cargo/luggage gate?
Answer: As you have pointed out, some airports have gates located at two levels. The upper gates have a jetway leading to the entry door of the aircraft. The lower gates (sometimes referred to colloquially as "ground level" [or similar] gates) exit directly onto the ramp whereupon passengers walk to the aircraft.
In my experience, for terminology consistency and ease of passenger terminal navigation, both lower and upper gates are all shown on airport departure/arrival monitors, boarding passes, etc., as "Gates."
Of course, there may be some airports that use a different naming convention (between upper and lower gates) but I have never encountered that.
Comment: Thank you for your answer 757tonga.
Answer: The parking spot of the aircraft on the ramp is commonly called a "stand".
The exit to the ramp (either directly to the aircraft via a jetbridge or to say a bus stop) is typically called a gate.
That's internationally accepted terminology, but I can't guarantee that there aren't airports or countries where other words are used (especially if languages other than English are the norm there, obviously).


Use "cd -" without any output

Question: How do I run the cd - command without echoing out any output?
I tried cd - 2>&1 /dev/null but that prints out the destination directory.
The reason for this is that I would like to use it an a bash function and I would prefer to not have the unnecessary output.
Answer: Try it like this:
cd - > /dev/null

You can also do:
cd - > uselessfile

This will send the output to the "uselessfile" file instead of to STDOUT.
You can also append instead of creating or overwriting the file.
cd - >> uselessfile

Answer: @erewok already answered the question, but I will take a stab at explaining what is actually happening and why you are seeing the behavior that you do.
The problem is with your redirection. You are writing:
cd - 2>&1 /dev/null

which because redirections can appear anywhere within the command line (you can confirm this yourself with something simple like echo a b 2>&1 c </etc/fstab d), after redirections are stripped actually becomes:
cd - /dev/null

See the problem? You are passing two arguments to cd, not one argument and two redirections. Since you can only ever be in one current directory at one time, cd only considers its first argument, which in this case is the -.
What you probably intended to write is a cd command with redirection of both stderr and stdout to /dev/null. There are two ways to do that.
The easiest in your case would be to simply inform the shell that you want redirection, by adding a > character. This is what @erewok is suggesting.
cd - 2>&1 >/dev/null

This first redirects stderr (file descriptor 2) into file descriptor 1 (stdout), then redirects stdout (implicit 1) into /dev/null. Note that the ordering is important; you won't get the same result if you reverse the redirections, though in some cases it may appear that you do because of how the particular program uses the respective output streams.
Alternatively, as has been suggested by @demure, you can use &> to redirect both streams at once if this syntax is supported by your shell.
cd - &>/dev/null

Do note that any of these alternatives will also silence the error when $OLDPWD no longer exists, since you are redirecting standard error output into the system black hole. If this is a concern, I would check $? afterwards; you should confirm this yourself if it is a real concern, but at least in my tests, a failed cd (whether cd $someplace or cd -) sets $? = 1 while after success $? = 0.
Answer: You can use:
cd ~-

According to the bash man page under Tilde Expansion:

If the tilde-prefix is a `~-', the value of the shell variable OLDPWD, if it is set, is substituted.
Comment: Weird but correct answer (for zsh too).
Answer: Maybe you can use
cd $OLDPWD

but in this case you'll need more typing :)
But you'll have an advantage: if there is any error the message will not redirect into /dev/null.
Comment: If `$OLDPWD` is unset, this will drop you in `~`. `cd -` will print an error (and presumably leave you where you already were).
Comment: You haven't right. If $OLDPWD is unset (why? maybe the user can unset this), the 'cd -' has same result as "cd $OLDPWD". Check the manual page ('cd -' is equivalent 'cd "$OLDPWD" && pwd'). Or you can test it :) 'OLDPWD="" ; cd -' - see you'll drop into ~ and print a ~ character.
Comment: I just tested it. On my system, the sequence `cd /tmp` `bash` `cd -` says `bash: cd: OLDPWD not set` at the second cd; whereas the sequence `cd /tmp` `bash` `cd $OLDPWD` drops you into ~ (almost certainly because $OLDPWD expands to an empty string). `cd $OLDPWD` will work fine once you have done at least one `cd` within the shell in question, but not before then.
Comment: Hm, yes, you've right. I've tested with zsh and with zsh doesn't drop error message.
Answer: Redirect stdout and stderr:
cd - &>/dev/null
the &> is the short hand version of cd - 2>/dev/null 1>&2, which I what I think you meant to use...

Note &> needs bash >= 4.0.

Ps. most commands can be pointed at locations, so it is unlikely you actually need to cd

Use "cd -" without any output


Why is an empty function considered a function?

Question: A function by definition is a set of ordered pairs, and also according the Kuratowski, an ordered pair $(x,y)$ is defined to be $$\{\{x\}, \{x,y\}\}.$$
Given $A\neq \varnothing$, and $\varnothing\colon \varnothing \rightarrow A$. I know $\varnothing \subseteq \varnothing \times A$, but still an empty set is not an ordered pair. How do you explain that an empty function is a function?
Comment: @Qiaochu, mathematical practice is more varied and flexible than your emphatic comment suggests. (See http://mathoverflow.net/questions/30381/definition-of-function/30397#30397.) Despite the occasional dogmatic insistance on the Bourbaki definition, almost no mathematical argument relies in any essential way on this co-domain-required concept of function, since one can simply specify a codomain whenever it is desired. Meanwhile, large parts of mathematics, including nearly 100% of the literature in logic and set theory, use principally the function-as-graph concept.
Comment: @Qiaochu, Oh, I wasn't at all suggesting that you were dogmatic, but rather just that this is a topic on which dogmatic views are sometimes expressed. To my way of thinking, however, there is very little at stake mathematically in the difference between the two definitions.
Comment: Well the definition of a function is a triple of sets $(A, B, C)$ where $C \subseteq A \times B$, and the elements in $C$ must satisfy certain condition (you know which condition I assume), here $A$ is the domain and $B$ the codomain of the function. The empty function makes perfect sense with this definition because even though as you say, the empty set is not an ordered pair, that does not matter because still $\emptyset \subseteq \emptyset \times B$. Yes, its "graph" is empty, it does not have ordered pairs, but there's no contradiction in the definition.
Comment: @JDH: fair enough. I don't like to think of myself as a dogmatic person, but there are certain perspectives that make things make sense to me and I generally explain things in terms of those perspectives. Of course there are other perspectives.
Comment: Maybe you should also read the Wikipedia entry for [empty function](http://en.wikipedia.org/wiki/Empty_function), where the last paragraph gives an example of where it appears in category theory.
Comment: @user11750: You have received several answers, if anything is missing from them please add it to the question or in comments to the answers, otherwise please accept one of the answers by clicking on the check mark below the vote counts on one of the answers (you can only accept one answer)
Comment: Notice that there are different set-theoretic ways to define a function. My preference is a set of ordered pairs satisfying certain conditions.Note that if you say that F is a set of ordered pairs you do NOT imply that F is not empty,only that it has no member that isn't an ordered pair.And the "certain conditions" on F do not imply that F is non-empty.
Comment: "an empty set is not an ordered pair." True. $\emptyset$ is not an ordered pair. But "$\emptyset$ is a set of ordered pairs", because $p\in\emptyset \ \Rightarrow\ p$ is an ordered pair (as $\not\exists p\in\emptyset:\ p$ is not an ordered pair).
Answer: One thing to point out is that a function is not just any set of ordered pairs; a binary relation is a set of ordered pairs. However, a function $F$ in this case is a special type of binary relation such that for every $x\in\text{dom }F$, there is a unique $y\in\text{ran }F$, such that $xFy$, or $(x,y)\in F$. But $\text{dom }\varnothing=\varnothing=\text{ran }\varnothing$. Can you find some $x\in\text{dom }\varnothing$ such there is not a unique $y\in\text{ran }\varnothing$ for which $x\varnothing y$? Since you cannot, $\varnothing$ is indeed a function.
Comment: @Get_Maths You can't. Not every set contains the empty set as _element_, but every set does contain the empty set as _subset_. A function from $A$ to $B$ maps elements in $A$ to elements in $B$, but not necessarily to subsets in $B$. If the empty set is not an element in $B$, then there cannot be a function mapping some element in $A$ to the empty set.
Comment: Hi , since empty set is present inside all sets , does this mean that when we do a mapping between domain and co-domain , then we can map any element to empty set also ? Means can we have pairs like (x,y) in which y is empty set while x is a proper element ? Please reply . Thanks
Answer: I believe that the answer lies hidden within the depth of "vacuously true argument".
An argument of the form $\forall x\varphi$ is true if and only if there is no $x$ such that $\lnot\varphi(x)$.
For example if our universe is the natural numbers with the usual $\ge$ order, then $\forall x(x\ge 0)$ is true because there are no negative numbers.
On the other hand, $\forall x(x\ge 0 \land x\neq 0)$ is false, simply because setting $x=0$ is a counterexample.
More generally, a sentence "If $p$ then $q$" ($p\implies q$, or $p\rightarrow q$) is true whenever the assumption is false, i.e. $p$ never occurs.
An example I often use is "If I am standing upside down from the ceiling right now, then you are all unicorns". It does not matter that I am talking to people, and not to unicorns, because I never stand upside down from the ceiling (it gives me a huge headache, you see).
The next point in our journey towards the empty function, is the bounded quantification. When we write $\forall x\in A(P(x))$ we actually write $\forall x(x\in A\rightarrow P(x))$, this means that we quantify over all the possible $x$, but if $x\notin A$ then we do not care about it anymore (the proposition is true since the assumption is false).
And lastly, the definition of a function $F$ is this:
$$\begin{align}
\forall z & (z\in F\rightarrow\exists x\exists y(z=\{\{x\},\{x,y\}\})\land\\ & \forall x(\exists z\exists y(z\in F\land z=\{\{x\},\{x,y\}\})\rightarrow \\ &\qquad(\forall u\forall v(\exists z\exists w((z\in F\land w\in F\land z= \{\{x\},\{x,v\}\}\land w=\{\{x\},\{x,u\}\})\rightarrow u=v)
\end{align}$$
Let's read this long formula. It says that $F$ is such that every element of $F$ is an ordered pair, and for every $x$, if there is an ordered pair $z$ with $x$ for left coordinate, then there is only one such pair (i.e. given two pairs, if their right coordinate is equal then they are equal).
Informally, $F$ is a function if it is a set of ordered pairs, that for every $x\in Dom(f)$ there is a unique $y$ such that $\langle x,y\rangle\in F$.
An example is $F=\{\langle 1,2\rangle\}$ is a function, all its members are ordered pairs, and since there is only one member it automatically satisfies the requirement that the left-coordinate determines the pair.
On the other hand $R=\{\langle 1,2\rangle,\langle 1,3\rangle\}$ is a set that indeed all its members are ordered pairs, but there are two distinct ordered pairs with $1$ in the left coordinate, so it is not a function.
And even more $A=\{3,\langle 1,2\rangle\}$ is clearly not a function, since $3$ is not an ordered pair!
The definition of a function is vacuously true when it is applied to the empty set, let us see why:

For all $z$ if $z\in\emptyset$ then $z$ is an ordered pair is vacuously true, as no $z$ is a member of the empty set.
Next we have, that for all $x$, if there is some ordered pair in the empty set, with $x$ as left coordinate then the right coordinate is unique, this is also vacuously true since there is no ordered pair in the empty set with $x$ in the left coordinate. This is exactly the case $p\rightarrow q$ and $p$ is false.

The conjunction of two true statement is true as well, therefore the empty set satisfies the requirement that every element of it is an ordered pair, and if two ordered pairs have the same left coordinate then they are equal. Therefore, $\emptyset$ is a function.
Comment: Maragila Hi , since empty set is present inside all sets , does this mean that when we do a mapping between domain and co-domain , then we can map any element to empty set also ? Means can we have pairs like (x,y) in which y is empty set while x is a proper element ? Please reply . Thanks
Answer: The empty set is a set of ordered pairs. It contains no ordered pairs but that's fine, in the same way that $\varnothing$ is a set of real numbers though $\varnothing$ does not contain a single real number.
Comment: Shouldn't it be "Though $\varnothing$ contains no real number"?
Comment: It might be worth pointing out that $\varnothing \times A = \varnothing$, so the empty function is the *unique* function $\varnothing \to A$.
Comment: ...so, *the* initial element in Set (--see http://en.wikipedia.org/wiki/Initial_and_terminal_objects)
Comment: Do you mean that "Every element of $\varnothing$ is a real number" by saying "$\varnothing$ is a set of real numbers"?
Comment: @Tedebbur It's the same.
Comment: This is because $\varnothing$ is an empty set of real numbers, right?
Comment: @Tedebbur It's an empty set (or rather, *the* empty set), and so a subset of the set of real numbers.


Is it possible to get dark elixir before Town Hall 7?

Question: Is it possible to get dark elixir before Town Hall 7? Is there any way to store it without having a dark elixir storage?
Answer: It is not possible to store Dark Elixir without a Dark Elixir Storage, so no, it is not possible to get Dark Elixir before Town Hall 7.  Appropriately, there is nothing you can spend Dark Elixir on before Town Hall 7 anyway.
Comment: It is possible to store Dark Elixir without a Dark Elixir Storage I believe. A level 7 Town Hall has internal storage for Dark Elixir, but that said its a level 7 Town Hall, which isn't available until you reach Town Hall 7. :P
Answer: Technically, you could get attacked by someone using dark elixir troops, and then not collect those headstones until you get to TH 7, but that would require extreme patience and willpower, so unless you have that, then no.
Answer: You could attack a base with dark elixir and steal it but without storage and dark barrack, it is useless. Also the chance of stealing is almost impossible as dark elixir is well protected.
Answer: NO.
When you attack a base and get Dark Elixir from it as a TH6 and below, the verdict (victory/defeat) screen will show you the amount of Dark Elixir you have stolen but since you have no storages as this can be only obtained starting at Town Hall Level 7, it simply disappears, just like when your other resource storages are full.


Repairing small damage to outside corners. Plaster walls.

Question: I'm thinking of using bondo. Is there a less-complex way to do it. I'm concerned that regular plaster material will fall off.
Answer: Use plaster, 2-part body filler will be just as likely to fall off upon impact and is more difficult to use (IMO).
Rough up the areas around the repair to improve adhesion. Moisten the existing damaged area before carefully applying plaster repair. Mix it to a firm putty consistency then use a moistened wide putty knife to "feather" the plaster back onto the adjacent wall areas. Sand smooth.
You might consider using a corner protector for areas subject to frequent bumps, they come in all colors and sizes including clear:
Comment: Good after-construction solutions.
Answer: The pro solution involves a metal corner reinforcement, which the plaster is brought flush with before painting. That harder surface is less likely to suffer damage from impact, and can usually just be spot-painted rather than needing to be repaired. But I'm not sure there's a good way to retrofit that.


DrawText in CGRect for PDF

Question: I'm trying to create a PDF and I have some text.  It is longer than one line, so I'm not sure how I need to write it into my context.  Do I calculate a CGRect the size of my text first?  From there, how would I do word wrap or things like that in creating a PDF?  So far all I've been able to do is to just draw a title at the correct location :-.  Thanks.
Answer: I recommend using Core Text, as this is a fairly powerful text rendering framework that plays nicely with Quartz. What you're trying to do is easily accomplished using the CTFrame class.

DrawText in CGRect for PDF


Develop outlook add-in compatible with multiple versions

Question: I created a VSTO outlook add-in under the outlook 2010. But seems it doesn't work when it was deployed to outlook 2007. The inefficient way to solve the problem is compiling again under the outlook 2007.Is there any better way to make it work in both versions? thanks
Answer: You only need to create one VSTO Outlook Add-in as per this article
Basically the new embedded interop types feature in Visual Studio 2010 help the Add-in to resolve the PIAs at run time. The only issue is that you need to code with the lower denominator (2007) or check the Outlook version in code and enable the 2010 required features.
Alternative: You may consider the use of a third-party-tool (www.add-in-express.com), this tool allows the creation of version-independent add-ins.
Answer: I have the same problem. What I have done is testing at the start of the addin (starup function) wether the version of outlook is 14 (for 2010) or not. But I had to install Office 2007 and compile again in an outlook 2007 project to see the result. The program is functional but I still have some errors.


Any way to revoke old key pair?

Question: There is a many-year-old 1024 DSA key in the public keyservers under my name. There is a 2048 ELG-E subkey for it. I didn't create these keys, they were created for me by a former employer without my consent. I don't have the private key and it apparently has no expiry date. (Just brilliant.) I know there is no way to remove them from the servers, but is there perhaps a way to crack them and issue revocation certificates? Is the cipher sufficiently aged/small to reasonably be able to crack them these days?
Comment: The former employer created the keys without your consent? You're truly suffering from a traumatic experience, I think $10 billion USD are just the beginnig helping to overcome this. I want 10% for this advice.
Answer: If you didn't create the keypair and never had the private key, then it's not your key; it's a fake that was created by a third party. Anyone can create an OpenPGP key under anyone's name without their consent and upload it to the public keyservers. The fact that this was done by your former employer is irrelevant (unless it means you can contact them and ask them nicely to revoke the key).
The real solution to this problem is the web of trust: your genuine key should be verified directly by your contacts and/or signed by others that they trust (and whose keys they have verified). If your contacts don't understand this, your private communications with them are already doomed, as they will be easily fooled when a malicious man-in-the-middle provides them with a fake key.
Answer: The only exploit I can find on 1024 DSA is a traffic sniffing attack via a flawed pRNG, and it's a little unreasonable.
(If you can crack PGP, let the rest of us know so we can run around with our hair on fire :P)
Here's some ways to mark this key as invalid. However, unless you can get your hands on a revocation certificate, those keys are cast into the void.
http://www.pgp.net/pgpnet/pgp-faq/pgp-faq-key-revocation.html#revocation-without-secret-key

Any way to revoke old key pair?


Smallest number recorded in a cell

Question: A value in a cell that changes automatically (using Google Finance), I want to record the lowest value in another cell.
Comment: Both Excel and Google Sheets have functions like MIN and MAX to find the smallest and highest number in a range.
Answer: You cannot create a permanent snapshot of a cell value with a spreadsheet formula, so you will have to use a script.
See the appendValuesToArchiveSheet script for one possible solution. You can use it to copy the value in the cell in another sheet in a log file of sorts on an hourly or daily basis and then apply min() function to get the lowest value.

Smallest number recorded in a cell


What rear mech can I use with 105 shifter?

Question: I would like to use a set of 105 shifters (10 speed), but I don't have a rear mech yet for them.
I would like to purchase a mech that would allow me to use a big cog cassette, like a cyclocross or mtb one.
What is the compatibility with other models, like mtb mechs?
Thanks in advance
Answer: It depends on what you mean by big, which can now be interpreted many ways.
Without doing anything too tricky, you can run them with any 9-speed Shimano mountain derailer, some of which can natively handle up to a 36t, RD-M592 being a currently made and easily available example.
10 and 11 speed Shimano mountain rear derailers use different actuation ratios, so they can't go directly on your shifter, but they could be made to work using something like a Jtek adapter or Wolf Tooth Tanpan. If you wanted to run a 40 or 42, you could use a Wolf Tooth Goatlink on an applicable 10-speed RD that you also have a cable pull adapter on.
If you want to use a road RD, you can go up to a 40 with a Wolf Tooth Roadlink. It's important to understand that they increase the clearance but not the capacity of your RD, so whether it makes sense depends on what's going on up front. (True no matter what route you choose actually.)
Comment: yes, yesterday I went on Sheldon Brown website and looked at the links about compatibility. Checking I realised that the 9 speed derailleur are perfect for mixing with road shifters.
I will probably get the one you suggested or similar, even considering that these 9speed items are still quite expensive (more than 10 speed derailleurs).
I will be using a standard MTB cassette, so up to 36t.
thanks for your help. I hoped there were more options. I have already a jtech, but those are quite pricey and not perfect, in the future I will probably opt for something different.
Thanks
Paolo


How to control nokia 5110 display using esp-01

Question: I am working on a smart device using esp-01 to pull data from internet and display on Nokia 5110 LCD display, and send back the resistive touch inputs to my server and display those on my lcd I am using an Arduino UNO as a secondary device that talks to esp-01, my display and the resistive touch panel. As the esp-01 has got a system on chip, I can program it and do most of the thing my UNO is doing, but because of lack of ports I am using UNO (as far as i know that's the only limitation.. I dont exactly know how is the analog pins on UNO different from the gpio pins on esp) is there any ways if I can do the whole task using only my esp-01 by eliminating UNO. If its only about the less gpio pins on esp-01, will I be able to eliminate UNO by using higher esp such as esp-07 or esp-12E? if not, could you suggest a best way of bi-directional communication between esp and UNO? (so that esp can sent the display info to uno and based on that info, uno can send the resistive touch inputs to esp)
Comment: Your question consists of multiple questions tossed around informative text. Also, it consists of multiple questions which are merely related and does not involve any schematics or diagrams to make visible what you mean. Try to make your question more concrete.
Answer: Yes, you can use a NodeMCU ESP12E board for example as a standalone microcontroller, you actually don't need an Arduino in your case.
Comment: Since the restive touch is connected on the analog inputs, will the esp still read the analog values?
Answer: The ESP-12 (don't know about other versions) does have one ADC pin.
https://github.com/esp8266/Arduino/blob/master/doc/reference.md#analog-input
I don't know how much your pins display needs. If this is more than one, then you will need a seperate ADC. There are many available as a single chip, but you could also use an arduino as you're doing now.


copy table from libreoffice calc in word document

Question: When I use libreoffice calc, I copy my table from libreoffice calc in libreoffice writer. But when I want to save de document in word type, the table was disappear.. So what must I do? cause almost all my friend didn't use libreoffice writer.. Thank you so much
Comment: I cannot reproduce the problem, even if I uncheck all MS compatibility options in `extra (from the menu) > options > load/save`, all tables & sheets etc are saved. you could try those settings nevertheless. Does the problem only occur on their computer or are the tables lost at your's too?
Answer: I'm not an expert on LibreOffice, but I believe the reason copying and pasting doesn't result in a visible table is that the table shown in Calc is merely an instrument (like ruler lines) rather than part of the document itself.
That said if you save the Calc file as .html then open the .html file in Writer and save as a document you can get a visible table, because it forces table to be written to the document as data.
Steps:

Open your Calc file and save as a .html file.
Open Writer and then open the .html file.
Save the file as a document (.odt, .doc, .docx, and etc).

Additional Resources:
Video of the process (MP4 1.70MB) = https://copy.com/s3JeFSJrR4pa


Why is the dog in The Call of the Wild done with CGI?

Question: In the new The Call of the Wild film, the dog is done with CGI which makes him look very cartoonish. I noticed throughout the film that other animals are also CGI, such as a rabbit and a dog team. It seems unnecessary to me, especially for a genre of film where actual animals have been used very effectively in the past. Is there any commentary on why this decision was made to use CGI animals instead of real ones?
Answer: From Screenrant:

London's adventure novel incorporates a lot of violent scenes, particularly when it comes to the dogs. The studio found a way to lessen the violence and scares so that they could create a family-friendly film that still hits on the themes of the classic tale. CGI and motion capture technology are getting more and more common and it most likely seemed like the easier option due to the vast reliance on animals for the movie. It's also important to note that The Call of The Wild wasn't shot on location and instead, was filmed on sets and green screens. Using CGI for Buck and the other four-legged stars were always part of the plan from the early stages of development.
Comment: That's too bad. It honestly cheapened the experience for me.


Is 40 minutes enough time to transfer at Newark (EWR)?

Question: We have been booked onto a flight from Orlando to Newark (EWR) due to arrive at 18.15. This is with United.
Our connecting flight (also with United) to take us home to the UK, is due to leave at 18.55.
This gives us 40 minutes transfer time and I'm worried this won't be enough.
can anybody help?

What terminal are we likely to arrive into and what terminal would we likely leave from?
Will our baggage be checked though automatically (as we are with United all the way), or will we have to collect it and check it back on to the UK flight?
Do you think I should contact the airline and /or travel agent and insist they find me an earlier flight from Orlando?

Many thanks for any help offered.
Comment: Is this also a transfer from terminal A to C?
Comment: @Bob If you have booked through a travel agent, why not ask him directly? That's the kind of things he is supposed to know.
Comment: @MarcelC. In this particular case probably not: http://flightaware.com/live/flight/UAL1288
Comment: I'm pretty sure that you will have to change terminals.  If memory serves (and things haven't changed since I flew internationally through Newark 5 years ago), there is a separate international terminal at Newark.  So you'll have to take the train, which may take 20 minutes. If you don't have to re-check your luggage, you may be okay, but it will be cutting it very close. On the return flight, 40 minutes is not nearly enough, as you must go through U.S. customs, and re-check your luggage before boarding your continuing flight.
Comment: @Flimzy There is no separate international terminal at EWR. Based on the question say that they are going "home to the UK", this IS their return flight - with no customs/immigration/luggage recheck.
Comment: @Flimzy United only uses the "International Terminal" or Terminal B for arrivals.  Departures are normally handled from Terminal C.  So at worst this will be a connection from A to C but more likely not even a terminal changes.  http://www.panynj.gov/airports/ewr-airlines.html
Answer: When looking at connections there's always 2 things you should keep in mind :

What are the odds of you not making the connection, and
What's the impact of not making it?

40 minutes at Newark for a Domestic -> International connection is plenty of time, presuming that your inbound flight is on time, and you're within the same terminal.
Flights from Orlando will almost always arrive in the C terminal, and flights to London will (almost?) always leave from terminal C - so you're covered there.
As for on-time - who can say?  There are websites that will give you historic information, but history isn't going to control whether your specific flight is on-time or not.
So all up, the odds of you making the connection are good.  Not excellent (if your inbound is more than 10-20 minutes late your odds drop significantly), but still good.
So what happens if you miss the flight?
Newark is a very major United hub.  They run multiple flights to London from there every day - especially in the evenings when flights depart as frequently as 1-2 hours apart!  Depending on the day, there will likely be 2 other direct flights to London after yours - and the airline will happily move you to one of those flights presuming there are seats available.
Yes, it's possible there won't be seats available - but odds are there will be, especially as it's likely someone from one of the later flights actually went "standby" on your original flight.
Yes, it's possible that you'll end up separated from your traveling companions, and in a middle seat.
But you'll almost certainly get on!
So what should you do?  Presuming you've already booked, I'd say go with it.  Changing flights is not going to be cheap, and the odds of them letting you do it for free due to the short connection are almost zero.
If you haven't booked, then it comes down to cost.  If you can get a later flight to Heathrow for the same price, I'd probably do it.  It'll get you in an hour or two later, but it'll be worth it for the piece of mind.  But if it's going to cost more, then I'd stick with the 40 minute connection - worst case you miss the flight and end up on a later one anyway!
If you were connecting to a location with less frequent services (eg, one-a-day rather than every few hours) then this would be a very different story!  In that case, make sure to allow yourself enough time as having to wait an extra 24 hours for the next flight isn't fun...
Answer: Personally, I would contact your travel agent and see if an earlier connection from MCO is available. You can also try the airline, although it may not be easy to change to an earlier flight without paying a change fee. On the day of travel, you can also attempt to get a Same-day Change (SDC) to an earlier flight.

Assuming you are booked on a single United ticket and are flying UA aircraft to the bitter end, you should be able to obtain your boarding passes in Orlando and have your baggage checked through to your final destination.
(On the other hand, as far as I know, United has no domestic airline partners in Britain since the demise of BMI, so if you have an onward connection, all bets are off. UA can interline baggage with BA, but not Flybe, for instance.)
Published minimum connection times… are nearly useless
Each airline maintains its own standard minimum connection times (MCTs) for various airports. The MCTs are only a standard measure for the itinerary construction process, however, to prevent people from booking truly impossible connections. Their relationship to reality is… aspirational for anyone other than a fit adult with light hand luggage taking no toilet breaks who's arrived on time and had no delay deplaning, walking briskly with boarding pass in hand for the connecting flight. For the rest of us, you may want to pad it by 25-50%.
Of course, United makes it nearly impossible to find out their MCT anyway (in pre-merger United it was 40 minutes at EWR), so perhaps the point is moot.
Terminals and gates
United's primary terminal at EWR is Terminal C, and as far as I can tell, all international flights would normally arrive and depart from C. As Terminal A is mostly used for United Express (commuter/feeder) flights, I suspect your Orlando flight would also use Terminal C. Wikipedia is a surprisingly reliable reference on such matters, having an army of aviation geeks keeping the pages for major hubs and major carriers pretty well updated.
Gate assignment is unpredictable, though a flight may use the same gate for a number of days or weeks at a time. United's own flight status tool is helpful here, as you can see the arrival and departure gates for your inbound and outbound connections over a period of days.
Ontime performance
It is extremely unlikely that any flight on a trunk route such as EWR-LHR will be held for connecting passengers, so an awareness of the reliability of your inbound flight is helpful.
FlightStats is a free tool that lets you compare flight delays and other information across flights, airports, airlines, and time. Newark is a highly congested airport, and delays accumulate throughout the day; this is borne out in stats that show that only around 72% of MCO-EWR flights are on time between 1500 and 1800, with an average delay of almost 45 minutes.
Comment: There is 6 direct flights every day: http://www.united.com/web/en-US/apps/travel/timetable/results.aspx?Origin=MCO&Destination=EWR&Date=5/21/2013&Time=&NonStop=&NumFlight=&FLN=


Is there a way to safely eject a USB hard drive from the lock screen?

Question: Often I come to my mac sitting on my desk in the morning and need to simply unplug it and put it in a bag. While maybe not strictly necessary to properly eject the attached USB drive, it sure would be nice if there were a way to do so without first logging in.
Answer: AFAIK there is no save way to eject an external drive from the lock screen.
You have several options though:

Purchase and install Mountain and enable "Unmount external volumes on sleep". The feature still seems to be experimental.
Create a LaunchDaemon which ejects your external drive(s) gracefully at say 5am. Here is an example of a bash script to start with:
<code>#!/bin/sh
/usr/sbin/diskutil list | grep -e 'disk[1-9]s.*' | sed 's/.*\(disk[0-9].*\)/\1/' | xargs -I{}
/usr/sbin/diskutil unmount {}
</code>
If you don't want to write a LaunchDaemon, Sleepwatcher should support your efforts.
Unmount all external volumes before setting your Mac(s) to sleep.
Comment: Thanks for all that.  Holding out in hopes someone does have a direct answer.  1-3 aren't ideal.


American Living Abroad not working for a US company, what kind of taxes do I pay?

Question: I am an US citizen living abroad, I understand that I need to pay taxes even abroad, but how do I pay taxes if I'm not working for a US company?
Answer: You still need to file. Fill out the PDF form from the IRS web site and mail it to them.
If you're working for an overseas company you can claim the Foreign Earned Income exclusion, which is about US$85,000 per year. If you earn less than that you will pay no tax on your overseas income to the IRS.
If you're self-employed, you will still need to pay the employers contribution to Social Security and Medicare, as these are not covered by the exclusion. I found this situation too hard to deal with on my own, and found a local accountant who specialises in US tax matters.


Uninstall MariaDB without removing databases

Question: I am running MariaDB 10.3 on Ubuntu 20.04.
Now MariaDB is not running and one database in it.
Can I uninstall the MariaDB 10.3 retaining database?
My plan is that install a higher version of MariaDB and get back the existing database.
If so, which commands do I have to apply?
Comment: Dump the database (`mysqldump databaseName > file.sql`) , reinstall MariaDB, and import the database (`mysql databaseName < file.sql`). Is that what you need?
Answer: I got the solution, uninstall MariaDB without deleting databases and reinstall it again.
sudo apt purge "mariadb*" -y
sudo apt autoremove -y
sudo apt-get install mariadb-server mariadb-client

Answer: mysqldump -u [username] -p [DATABASE name] > [backup filename].sql

mysql -u [username] -p [DATABASE name] < [backup filename].sql

Comment: MariaDB service is not running because of mysqld.sock problem. MySQL dump command will not work.


For a semiconductor, why does a band gap larger than the incident photon energy mean material transparency?

Question: If a photon with less energy than a band gap hits the band gap, why will the material be transparent? Although the photon cannot raise an electron in the conduction band to the valence band, why isn't the photon absorbed and turned into heat?
Comment: How is absorbed?
Comment: @JonCuster For example, my imagination says it can cause movement to the atoms themselves
Answer: The answer is contained in the question: in order to be absorbed the photon needs to raise an electron from the valence band to the conduction band.
Absorption here means transmitting the photon energy and momentum to the semiconductor. Being an electromagnetic wave, the photon is coupled to the charge in the semiconductor, and the only possible change of the charge state is moving an electron to a different energy state. This is not a problem in metals, where the conduction band is only partially filled and electrons can be excited to any energy within this band, which is why metals are reflecting in the visual spectrum.


How to make tags visible

Question: I'm trying to make certain tags that certain players get but I want them to be visible above the players head, and as far as I know that doesn't naturally happen, is there some sort of command or option to make custom tags visible above name tags or anything like that?
Comment: Like scoreboard objectives?
Answer: Bedrock Edition
No, unfortunately there is no direct or easy way to do this with tags that you apply through /tag. The only thing you can do is set a scoreboard objective to be above a players head.
However, it might still be possible, thanks to add-ons.
You could add the various tags as various custom particles. Next, change the player model, animations and animation controllers to include these particles, probably based on whether they have the tag or not.
I am not sure if you can detect tags in animation controllers directly, if not you'll need to work around this by adding environment_sensors to the player entity that checks for the various tags being present (or not) and adding a corresponding component group  with an attribute that is detectable in animation controllers, but that otherwise doesn't affect game-play.
Here is the official documentation / guide on particles, which also includes explanations on how to add them to entities:
https://learn.microsoft.com/en-us/minecraft/creator/documents/particleeffects
Java Edition
A possible workaround would be to use Area Effect Clouds / Armor Stands or even better the upcoming 1.19.4 Display entity to display the tags in an entity name, while constantly teleporting the entity above the player. This will visually lag behind a bit, but it is a possible solution.
Alternatively you could think about two things (if you only need one tag to be displayed at a time):

you can set one scoreboard objective to be displayed above the players heads.
Teams let you set pre- and suffixes, which appear around the players name above their heads. So you could set the prefix to [tag]  and players in this team would look like [tag] Playername in-game.

How to make tags visible


is it right to combine javascript frameworks?

Question: I am wondering if it is OK to use multiple javascript frameworks for example (jQuery, Raphael) in the same script (handling event & ajax with jQuery and drawing with Raphael) ?
Answer: Raphael isn't really a framework. It's a specialized library.
When it comes to mixing frameworks, then it is usually a bad idea.
While you can usually persuade them to run without conflicting, you end using a lot of code that does the same job as a lot of other code in the page. This adds a lot of overhead to the page, which is bad for performance.
Comment: +1, there's very little point in combining the big frameworks. It's a lot of extra work for little gain. If a framework is missing something you think it should have, create a plugin for it.
Answer: Yeah it's fine. jQuery will happily not bind to $ if you ask it (and need it):
jQuery.noConflict();

Answer: I don't think there's any problem about it since Raphael's demo already uses jQuery : http://raphaeljs.com/analytics.html (look at code source).
Comment: well, Raphael was just an example... ;)
Comment: Ok so other answers seems better :)
Answer: If you have good reason to do so: yes. Such a reason would be that both frameworks have different features. Obviously you should only use stable frameworks that have no known issues of interference with other frameworks (or provide a way to avoid interference, like jQuery does with the noConflict method)...
Anyway it might not be a bad idea to search the jQuery plugin directory (plugins.jquery.com) to see if there's anything available like Raphael, or maybe a plugin that integrates Raphael with jQuery before combining the two yourself...


How does voting work when shares are lent out to short sellers?

Question: At a stock brokerage firm, A has 1000 shares of a stock in a margin account, while B has 500 shares. The stock brokerage firm holds all these shares in street name and can lend these shares to short sellers at any time. The firm has lent 600 shares to short sellers, but A and B now want to vote in a proposal. Do A and B get to vote using the remaining 900 shares in proportion to the number of shares they own (A can vote using 600 shares, B can vote using 300 shares)? How does voting work when some of the shares have been lent to short sellers?
Comment: The broker decides how to match the short shares, he may use all of A; best fit .... or 50-50 from both A and  B, unlikely... or FIFO .... whoever's pledged first... These are firm allocations as the ownership changes in short sell.
Answer: The purchaser of the shares sold short is the holder of record and is entitled to the voting rights and the dividend. When the short position is closed, the borrowed shares are returned to the lender  and the dividend and voting rights return to the initial owner.
Comment: Shares in a cash account are not loaned out. Last I knew, margin account shares could be loaned unless the account holder designated that they could not be loaned out.  However, I do not know current regs for lending shares  so the best thing to do if you have a margin account and you do not want your shares loaned out, call your broker and get the scoop.
Comment: Does that mean my shares won't be lent out to short sellers without my broker asking me ?


When a ysoki is holding items in his cheek pouches, can others tell if they have something in there?

Question: The rules on ysoki cheek pouches are rather vague on whether objects held inside them are actually concealed. It seems possible that someone else would be able to determine that the ysoki was concealing something either by visible bulge or by the impact the object has on the ysoki's speech. Is there any published Starfinder source that addresses this question? If not, is there anything about rodent biology that suggests a good ruling?
Answer: There are no further rules on this
A search of available material suggests that this ability seems to be largely up to GM interpretation, beyond the Bulk limit. There are no further mention of it in the Ysoki material nor any of the search results for cheek pouch(s) on Nethys.
Real-world rodents with cheek storage are very obvious
As you can see in this Youtube Video, even a single significant sized object is quite apparent.
Comment: That video is really something! I'm not sure I would rule that a single L item was noticeable, but certainly a ysoki carrying close to capacity would be noticeable.
Comment: I'd say it depends on the object if I were running the game. A cestus battleglove would be far easier to miss than an acid cannon pistol, for instance. As long as the players understand that their cheeks may get checked by savvy NPC's, it would be pretty difficult to break the game with the ability so I'd lean toward fitting the narrative.
Answer: From a rules perspective, there's no differentiation between a Ysoki cheek-pouch and any other quick-access pocket, thus it would be a normally-contested sleight-of-hand check to conceal an object of light bulk there. Anything larger would be readily-apparent.