"That might even could happen" be considered incorrect?
Is “might could” a correct construct?
Accepted answer appearing below top voted Accoring to Joseph Wright's answer at   The k-type argument has recently been adjusted: you now want e-type  Questions:  What is the functionality of the new e-type argument and how does it differ from the previous k-type argument?  The 2016-11-21 version of the xparse documentation does not mention the k-type argument at all. Is the plan to leave the earlier k functionality intact (but deprecated so no documentation) or will it eventually be removed and any usage of that should eliminated? If the plan is for it to be removed, how long will the older k-type argument functionality be kept in xparse.   Code: Example of the k-type argument from . Would be useful to see how this would be modified to use the new e-type argument. \documentclass{article}  \usepackage{amsmath} \usepackage{xparse} \usepackage{xcolor}  \NewDocumentCommand\MyMacro{k_}{%     \IfNoValueTF{#1}{%         \mathbf{A}     }{%         A_{\textcolor{red}{#1}}     }% }  \begin{document}  With a subscript: $\MyMacro_{\pi}$   Without any subscript: $\MyMacro$   \end{document} CreateService get error: ERROR_INVALID_ADDRESS (0x000001e7) Why isn't the 'len' function inherited by dictionaries and lists in Python example:  a_list = [1, 2, 3] a_list.len() # doesn't work len(a_list) # works   Python being (very) object oriented, I don't understand why the 'len' function isn't inherited by the object.  Plus I keep trying the wrong solution since it appears as the logical one to me Related:   I have put a bit of commentary enumerating my confusions in parentheses  I read in Black Holes and Time Warps (Kip Thorne), that quasars can generate their jets from four different processes. These all involved the accretion disk, but there was one which doesn't make quite as much sense. It was called the Blandford-Znajek process, and it involved magnetic field lines carrying current.  The process was visualized in two ways. A black hole, with magnetic field lines, is spinning. In the first visualisation (viewpoint actually), the magnetic field lines 'spin' along with the black hole, and nearby plasma is anchored onto the field lines by electrical forces (where did the electrical fields come from?). The plasma can slide along the field lines but not across them (why?).  Since the field lines are spinning, centrifugal forces will fling them up and down the field lines, forming jets.  The other viewpoint is this, and it makes even less sense (to me that is, I haven't had a formal education in GR): The magnetic fields and the swirl of space generate a voltage difference across the field lines (Why? How?). The voltage carries current across the magnetic field lines (why are the field lines behaving like wires?). This current travels across plasma, which accelerates it, creating the jets.  Now the main thing that doesn't make sense, is that magnetic field lines are behaving like wires. Why would they? I suspect the answer lies hidden somewhere in the equivalence of EM waves in different frames, but I can't think up any convincing argument from that side.  If the answer involves GR equations, you don't need to solve it here (wouldn't make sense to me), but if you have to, just refer to the equation and what you did to it, along with the final result. Thanks! For example i have the domainname buyhouse.com The keywords "buy house new york"  buyhouse.com/new-york/   buyhouse.com/buy-house-new-york/   Whats the best url option for SEO? Do different databases use different name quote? For example, mysql quote table name using   SELECT * FROM `table_name`;   notice the `   Does other database ever use different char to quote their table name How to view the user's status? Deleting an element from an array in PHP Is there an easy way to delete an element from an array using PHP, such that foreach ($array) no longer includes that element?  I thought that setting it to null would do it, but apparently it does not work. My website's google cache copy looks broken.   Below is link to cache.  http://webcache.googleusercontent.com/search?q=cache:http://paintcollar.com  Can this affect the SERPs and crawling by google?  What can I do to rectify it?  PS. Few pages are being cached properly though.Below is URL to one such page. http://webcache.googleusercontent.com/search?q=cache:http://paintcollar.com/aneel How is Google Scholar compared to other academic search engines and catalogues such as ScienceDirect, Scopus, and universities' own online catalogues--in terms of the following?   comprehensiveness of search (i.e. can fetch all the ever published relevant titles, whether the user have access to full-texts or not) accuracy and precision of results advanced search features usability  Are there good reasons for (or against) using Google Scholar as the only literature search tool for PhD research? Does the answer of (2) depend on the research discipline? crisscross, dillydally, riffraff, etc Some English words only differ in their vowels: crisscross, dillydally, riffraff, etc. Is there a name for them? Redirecting stdout to a file you don't have write permission on When you attempt to modify a file without having write permissions on it, you get an error:  &gt; touch /tmp/foo &amp;&amp; sudo chown root /tmp/foo &gt; echo test &gt; /tmp/foo zsh: permission denied: /tmp/foo   Sudoing doesn't help, because it runs the command as root, but the shell handles redirecting stdout and opens the file as you anyway:  &gt; sudo echo test &gt; /tmp/foo zsh: permission denied: /tmp/foo   Is there an easy way to redirect stdout to a file you don't have permission to write to, besides opening a shell as root and manipulating the file that way?  &gt; sudo su # echo test &gt; /tmp/foo How do you read C declarations? Is there any difference between mapping and function? I wonder if there is any difference between mapping and a function. Somebody told me that the only difference is that mapping can be from any set to any set, but function must be from $\mathbb R$ to $\mathbb R$. But I am not ok with this answer. I need a simple way to explain the differences between mapping and function to a lay man together with some illustration (if possible).  Thanks for any help. What happens when a field turns on or off? Short Setup  I am curious about the the mechanics of fields, whether , , etc.  So as a specific example in order to simplify (hopefully) how to ask this question, consider  or , specifically interactions between .  My specific curiosity is in how we handle the "sudden" creation or loss of a source and how the source then creates its associated field.  My naive guess is that the loss of a source (e.g., annihilation) might be easier to handle, but let's focus on creation of a source for now.  Questions  The specific example of pair production interested me because I was wondering:   How does the field arise from the sources?   Meaning, is it delayed until after the source  fully "condenses" from the , for instance? Or does the field slowly "turn on" as the source "condenses"?   Perhaps I should have asked whether it we know if it takes time for sources to form (I assume it does).  If so, can we describe this from first principles or is it empirically based?  Am I asking that in a very uncomfortable manner?  If so, I would appreciate any suggestions.  For instance, is there a better word than "condense"?  I was thinking about water condensation as a very loose analogy to the purpose of the Higgs field in the formation of massive objects.  Why can they be produced without immediately recombining?   That is, how "close" are the two sources spatially after formation and what energies are needed to overcome the associated potential?  Does the field emanate/propagate as if from a point source?   I ask because I am trying to determine whether this is a simple  issue (i.e., far away it's just like a point source) or if the field emanates only from the "surface" of the source (e.g., ). If it starts from "within" the source as the source forms, do we know how to handle this mathematically?   My concern arises from the "similar" problem of bubble formation, where the bubble starts with zero radius which would require an infinite energy.  Perhaps the analogy is not appropriate?     Purpose  I ask these questions because it struck me this morning, while driving to work, that I did not know how and when a field "turned on."  I started to think about pair production and then quickly became confused (not difficult to do) and thought many of the quantum whisperers on this site would be much better at explaining these nuances than any of my failed rummaging through Wikipedia or scholarly articles and old text books. In PHP, function parameters can be passed by reference by prepending an ampersand to the parameter in the function declaration, like so:  function foo(&amp;$bar) {     // ... }   Now, I am aware that this is not designed to improve performance, but to allow functions to change variables that are normally out of their scope.  Instead, PHP seems to use Copy On Write to avoid copying objects (and maybe also arrays) until they are changed. So, for functions that do not change their parameters, the effect should be the same as if you had passed them by reference.  However, I was wondering if the Copy On Write logic maybe is shortcircuited on pass-by-reference and whether that has any performance impact.  ETA: To be sure, I assume that it's not faster, and I am well aware that this is not what references are for. So I think my own guesses are quite good, I'm just looking for an answer from someone who really knows what's definitely happening under the hood. In five years of PHP development, I've always found it hard to get quality information on PHP internals short from reading the source. Every subspace of a vector space has a complement I want to see if my proof is true or I thought very trivially?    If $H$ is a subspace of a finite dimensional vector space $V$, show there is a subspace $K$ such that $H\cap K=0$ and $H+K=V$    So far I have tried :    $H\subseteq V$ is a subspace $\Rightarrow\,\exists\;K=(V-H)\subseteq V$ $K$ is a subspace because it's the sum of two subspace $V$ and $(-H)$ Now we should prove that $H\cap K=0$ We assume $H\cap K\neq0\Rightarrow\exists\,\vec u\neq0\,,\,\vec u\in H\cap K$ $\vec u\in H\cap K\Rightarrow \begin{cases}\vec u\in H\\\vec u\in K\,\Rightarrow\vec u\in V-H\Rightarrow\vec u\in V,\,\vec u\notin H\end{cases}$ That's a contradiction so our hypothesis was wrong and $\vec u=0$ Can I travel to France with Fiktionsbescheinigung (Fiction Certificate) of Germany Assume you have some objects which have several fields they can be compared by:  public class Person {      private String firstName;     private String lastName;     private String age;      /* Constructors */      /* Methods */  }   So in this example, when you ask if:  a.compareTo(b) &gt; 0   you might be asking if a's last name comes before b's, or if a is older than b, etc...  What is the cleanest way to enable multiple comparison between these kinds of objects without adding unnecessary clutter or overhead?   java.lang.Comparable interface allows comparison by one field only Adding numerous compare methods (i.e. compareByFirstName(), compareByAge(), etc...) is cluttered in my opinion.   So what is the best way to go about this?