Do US/Iran dual citizens have a problem re-entering US?
Are dual US citizens affected by President Trump's ban on Iran, Iraq, Libya, Somalia, Sudan, Syria, Yemen?
Chromatic Number The smallest number of colors needed to color a graph $G$ is called its chromatic number, and is often denoted $\chi(G)$.  Show that if graph $G$ is simple, then $$ \chi \ge \frac{V^2}{V^2 - 2E}. $$ File1:  .tid.setnr := 1123  .tid.setnr := 3345  .tid.setnr := 5431 .tid.setnr := 89323   File2:  .tid.info := 12 .tid.info := 3 .tid.info := 44 .tid.info := 60   Output file:  .tid.info := 12 .tid.setnr := 1123 .tid.info := 3 .tid.setnr := 3345 .tid.info := 44 .tid.setnr := 5431 .tid.info := 60 .tid.setnr := 89323 Can you add new statements to Python's syntax? Can you add new statements (like print, raise, with) to Python's syntax?  Say, to allow..  mystatement "Something"   Or,  new_if True:     print "example"   Not so much if you should, but rather if it's possible (short of modifying the python interpreters code) Undo a particular commit in Git that's been pushed to remote repos Java: Avoid inserting duplicate in arraylist Zero visibility while editing a message in a chat room counting with max and min restrictions $$x_1 + x_2 + x_3 + x_4 = 10$$ But $x_1 \ge 1$ and $x_2 \ge2$.  Finally, $x_1&lt;6,  x_2&lt;6, x_3&lt;6$ and $x_4&lt;6$.  I started off by finding the total amount that you can get for the original equation. That would be $C (13, 3)$. Then i calculated for the cases of numbers being greater than or equal to 5. I dont know how to incorporate $x_1\ge1$ and $x_2\ge2$. Any help?  $x_1, x_2, x_3, x_4$ are all integers that could be >= 0(But $x_1$ and $x_2$ have their own restriction). How do I use itertools.groupby()? I haven't been able to find an understandable explanation of how to actually use Python's itertools.groupby() function.  What I'm trying to do is this:  Take a list - in this case, the children of an objectified lxml element Divide it into groups based on some criteria Then later iterate over each of these groups separately.  I've reviewed , but I've had trouble trying to apply them beyond a simple list of numbers. So, how do I use of itertools.groupby()?  Is there another technique I should be using?  Pointers to good &quot;prerequisite&quot; reading would also be appreciated. Generating data with a given sample covariance matrix I used a  for Photoshop, and was able to create some boxes with it. These boxes were shaped in the form of Software Boxes, while I require Customized Dimensions Boxes, which currently I'm trying to create with .   This software creates a box with no Reflection, and I disabled shadows in it, cause it doesn't allow transparency while saving to png. It allows custom dimensions, rotation, etc settings, but doesn't save transparency or reflections.  Here's the difference in output from both the above mentioned apps.. I'm trying to get the reflection + shadow in the 3D box Generator to the Protomissume generated image.   My question: How can I create similar Reflection &amp; Shadow in Photoshop?   Images:  3D Box Generator   Protomissume Box Shot   Thanks for any help.  Here are the Box Shot images (Photoshop, Protomissume) :  [  ] “The group of fifty people {is / are} going to arrive Thursday” - which is preferred? Isn't the following sentence grammatically correct?     The group of fifty people are going to arrive Thursday.   What's wrong with it? Someone said it should be      The group of fifty people is going to arrive Thursday.   Why? People is plural so why is people is better than people are? How do I get jQuery to select elements with a . (period) in their ID? Given the following classes and controller action method:  public School {   public Int32 ID { get; set; }   publig String Name { get; set; }   public Address Address { get; set; } }  public class Address {   public string Street1 { get; set; }   public string City { get; set; }   public String ZipCode { get; set; }   public String State { get; set; }   public String Country { get; set; } }  [Authorize(Roles = "SchoolEditor")] [AcceptVerbs(HttpVerbs.Post)] public SchoolResponse Edit(Int32 id, FormCollection form) {   School school = GetSchoolFromRepository(id);    UpdateModel(school, form);    return new SchoolResponse() { School = school }; }   And the following form:  &lt;form method="post"&gt;   School: &lt;%= Html.TextBox("Name") %&gt;&lt;br /&gt;   Street: &lt;%= Html.TextBox("Address.Street") %&gt;&lt;br /&gt;   City:  &lt;%= Html.TextBox("Address.City") %&gt;&lt;br /&gt;   Zip Code: &lt;%= Html.TextBox("Address.ZipCode") %&gt;&lt;br /&gt;   Sate: &lt;select id="Address.State"&gt;&lt;/select&gt;&lt;br /&gt;   Country: &lt;select id="Address.Country"&gt;&lt;/select&gt;&lt;br /&gt; &lt;/form&gt;   I am able to update both the School instance and the Address member of the school.  This is quite nice!  Thank you ASP.NET MVC team!  However, how do I use jQuery to select the drop down list so that I can pre-fill it?  I realize that I could do this server side but there will be other dynamic elements on the page that affect the list.  The following is what I have so far, and it does not work as the selectors don't seem to match the IDs:  $(function() {   $.getJSON("/Location/GetCountryList", null, function(data) {     $("#Address.Country").fillSelect(data);   });   $("#Address.Country").change(function() {     $.getJSON("/Location/GetRegionsForCountry", { country: $(this).val() }, function(data) {       $("#Address.State").fillSelect(data);     });   }); }); Thesis running problem in KILE I'm using  editor. There is no problem when I run others  .tex article in Kile. But problem is when I run a thesis article in KILE. This thesis article is running fine in      \documentclass[12pt,a4paper]{thesis}     \usepackage{amsmath}\usepackage{amssymb}     \usepackage{graphicx}   Is there anything need to add in KILE setting to run the Thesis .tex in KILE?  This is the log file:  This is pdfTeX, Version 3.1415926-1.40.10 (TeX Live 2009/Debian) (format=latex 2013.3.7)  25 AUG 2013 23:37 entering extended mode  %&amp;-line parsing enabled. **Thesis-Aug24-2013.tex (./Thesis-Aug24-2013.tex LaTeX2e &lt;2009/09/24&gt; Babel &lt;v3.8l&gt; and hyphenation patterns for english, usenglishmax, dumylang, noh yphenation, loaded.  ! LaTeX Error: File `thesis.cls' not found.  Type X to quit or &lt;RETURN&gt; to proceed, or enter new name. (Default extension: cls)  Enter file name:  ! Emergency stop. &lt;read *&gt;   l.2 \usepackage                {amsmath}\usepackage{amssymb}^^M *** (cannot \read from terminal in nonstop modes)   Here is how much of TeX's memory you used:  10 strings out of 495062  226 string characters out of 1182645  45108 words of memory out of 3000000  3285 multiletter control sequences out of 15000+50000  3640 words of font info for 14 fonts, out of 3000000 for 9000  28 hyphenation exceptions out of 8191  10i,0n,7p,80b,8s stack positions out of 5000i,500n,10000p,200000b,50000s No pages of output. When i tried to install PIP for python3 in Ubuntu 18.04.2 LTS  Command I used:   root@DESKTOP-0BEE3OD:/mnt/c# apt install python3-pip  E: Could not read response to hello message from hook [ ! -f /usr/bin/snap ] || /usr/bin/snap advise-snap --from-apt 2&gt;/dev/null || true: Success   I am not able to fix this error. Encouraging people to explain downvotes Note: If you're looking for a simple explanation as to why comments aren't required on downvotes, see .   I used to get "upset" (though that is too strong a term) when I got downvoted without comment. If my answer isn't good enough then I'd like to know why. Not only does it improve the answer for the OP but it improves my knowledge too.  Where the down-vote has been explained I've found it useful &amp; it has improved my answer, or forced me to delete the answer if it was totally wrong.  So is there any way we can encourage people to leave a comment? Perhaps they don't lose rep if they explain their down-vote?  I must admit though that I haven't always explained my down-vote either so you could call me a hypocrite. I've also grown a thicker skin over the months of using SO (it seems to have come with the higher rep score ;-)), so I'm less bothered about this now. Asking a question: DO or ARE? When should you ask a question with &quot;do&quot;, and when with &quot;are&quot;?  In other words,  Are you going to Spain next week?   Do you like Chinese food?  What is the rule here?  We don't say  Do you go to Spain next week?   Are you liking Chinese food?  Why is that? How exactly does Knuth's Up-Arrow notation work? A question about the arctangent addition formula. In the arctangent formula, we have that:  $$\arctan{u}+\arctan{v}=\arctan\left(\frac{u+v}{1-uv}\right)$$  however, only for $uv&lt;1$. My question is: where does this condition come from? The situation is obvious for $uv=1$, but why the inequality?  One of the possibilities I considered was as following: the arctangent addition formula is derived from the formula:  $$\tan\left(\alpha+\beta\right)=\frac{\tan{\alpha}+\tan{\beta}}{1-\tan{\alpha}\tan{\beta}}.$$  Hence, if we put $u=\tan{\alpha}$ and $v=\tan{\beta}$ (which we do in order to obtain the arctangent addition formula from the one above), the condition that $uv&lt;1$ would mean $\tan\alpha\tan\beta&lt;1$, which, in turn, would imply (thought I am NOT sure about this), that $-\pi/2&lt;\alpha+\beta&lt;\pi/2$, i.e. that we have to stay in the same period of tangent.  However, even if the above were true, I still do not see why we have to stay in the same period of tangent for the formula for $\tan(\alpha+\beta)$ to hold. I would be thankful for a thorough explanation. Determining the Orbits/Orbit Space of $O(3)$ on Real 3 by 3 Traceless Symmetric Matrices Let $O(n)$ be the set of $3 \times 3$ orthogonal matrices, and $S$ be the set of traceless real symmetric $3 \times 3$ matrices.  Now  $O(n)$ will act on $S$ by conjugation. Note that by the spectral theorem $ \forall A \in S$ in the orbit of $A$ there is a diagonal matrix $D=diag(\lambda_1, \lambda_2,\lambda_3)$ with $\lambda_1\le\lambda_2 \le\lambda_3 $.  Determine the all the orbits of the action &amp; the orbit space of the action.  What I've done:  Since all elements of $S$ are diagonlizable that the orbit of any element should be the orbit of its' diagonalized form because $\forall A \in S,   \exists P \in O(3)$ st  $PAP^t=D $ with $D$ a diagonal matrix and moreover for any other  $Q\in O(3)$ we get $QDQ^t=QPAP^tQ^t=(QP)A(QP)^t=RAR^t$.   And so would that imply the orbit space is just the set of traceless diagonal matrices as $tr(QDQ^t)=tr(DQ^tQ)=tr(Q)$ (cyclic property of trace) and $Q\in S$.  Any help is appreciated. Lightning-Web-Components Select Option prepopulate value Let's say I have a Lightning-Web-Component with a select list with dynamic options where the value is a user Id and the label is the user's name:  &lt;select class="slds-select" onchange={handleSelectChange} disabled={isDisabled}                           data-value={step.selectedUser} &gt;                                 &lt;option value=""&gt;--None--&lt;/option&gt;                                 &lt;template for:each={step.approvalTemplateStep.Approval_Step_Users__r} for:item="user"&gt;                                     &lt;option key={user.key} value={user.User__c}&gt;                                         {user.User__r.Name}&lt;/option&gt;                                 &lt;/template&gt;                             &lt;/select&gt;    How do I prepopulate the select option with a value? I have the value I want to be prepopulated in the variable called step.selectedUser.  Here's what I see on page load:   Here's what I should see: