why we don't use "s" when we question
doesn't has to /have to
Do the laws of physics evolve? How can I read my hard drive’s SMART status in Windows 7? How can I read the  S.M.A.R.T. state of my HDDs while using Windows 7, either automatically or manually? LM393 voltage comparator is not working Finding the variable name passed to a function Let me use the following example to explain my question: public string ExampleFunction(string Variable) {     return something; }  string WhatIsMyName = &quot;Hello World&quot;; string Hello = ExampleFunction(WhatIsMyName);  When I pass the variable WhatIsMyName to the ExampleFunction, I want to be able to get a string of the original variable's name. Perhaps something like: Variable.OriginalName.ToString()  Is there any way to do this? How to show hyperlink in LWC toast Proving there are infinitely many pairs of square-full consecutive integers So the question goes like this :  A positive integer $n$ is called square-full if for every prime $p$, $p \, | \, n$ implies $p^2 \, | \, n$, i.e. every prime power factor of $n$ occurs at least at the second power. This is equivalent to saying that there is no prime $p$ such that $p \, \| \, n$.  Show that there are infinitely many consecutive pairs of square-full numbers, i.e. infinitely many $n$ such that $n$ and $n+1$ are square-full.  The context of the question highly suggests that this can be proved by induction and it is the solution that I am looking for. It is not a homework, just something that caught my attention because I couldn't find any natural answer to it... I hope I'm not missing something trivial!  I've tried assuming $n_1, n_2, \dots, n_k$ were the first $n_k$ integers such that $n_i$ and $n_i+1$ are square-full, and then generate some polynomial in those $2k$ integers to get a new couple $n_{k+1}$, $n_{k+1} + 1$ but after a few natural tries I got nothing good out of it. Any ideas? I have an object already created in blender, a tree, or a human, or a pipe.. and I need this to be drilled with multiple holes.   The holes are painted in an image, that is, it is an image that has a repeating an images pattern (they can be circles, squares, or any form).  Here are some examples for drilling-pattern: I'm trying to change the cpu frequency on my laptop (running Linux), and not having any success. Here are some details:    # uname -a Linux yoga 3.12.21-gentoo-r1 #4 SMP Thu Jul 10 17:32:31 HKT 2014 x86_64 Intel(R) Core(TM) i5-3317U CPU @ 1.70GHz GenuineIntel GNU/Linux  # cpufreq-info cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009 Report errors and bugs to cpufreq@vger.kernel.org, please. analyzing CPU 0:   driver: intel_pstate   CPUs which run at the same hardware frequency: 0   CPUs which need to have their frequency coordinated by software: 0   maximum transition latency: 0.97 ms.   hardware limits: 800 MHz - 2.60 GHz   available cpufreq governors: performance, powersave   current policy: frequency should be within 800 MHz and 2.60 GHz.                   The governor "powersave" may decide which speed to use                   within this range.   current CPU frequency is 2.42 GHz (asserted by call to hardware). (similar information for cpus 1, 2 and 3)  # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors performance powersave   I initially had the userspace governor built into the kernel, but then I also tried building it as a module (with the same results); it was loaded while running the above commands (and I couldn't find any system messages when loading it):  # lsmod Module                  Size  Used by cpufreq_userspace       1525  0 (some other modules)   And here are the commands I tried for changing the frequency:  # cpufreq-set -f 800MHz Error setting new values. Common errors: - Do you have proper administration rights? (super-user?) - Is the governor you requested available and modprobed? - Trying to set an invalid policy? - Trying to set a specific frequency, but userspace governor is not available,    for example because of hardware which cannot be set to a specific frequency    or because the userspace governor isn't loaded?  # cpufreq-set -g userspace   Error setting new values. Common errors: - Do you have proper administration rights? (super-user?) - Is the governor you requested available and modprobed? - Trying to set an invalid policy? - Trying to set a specific frequency, but userspace governor is not available,    for example because of hardware which cannot be set to a specific frequency    or because the userspace governor isn't loaded?   Any ideas? Exercise 3.5.12. Let $ f: \mathbb N \times \mathbb N \to \mathbb N$ be a function, and let c be a natural number. Show that there exists a function $a:\mathbb N\to \mathbb N$ such that $$a(0)=c$$ and $$a(n++)=f(n,a(n))\;for\;all\;n\in \mathbb N,$$ and furthermore that this function is unique. Tao gives the hint: first show inductively, by a modification of the proof of Lemma 3.5.12, that for every natural number $N\in \mathbb N$, there exists a unique function $a_N:\{ n\in \mathbb N:n\lt N\}\to \mathbb N $ such that $a_N(0)=c$ and $ a_N(n++)=f(n,a(n))$ for all $n\in \mathbb N$ such that $n\lt N$.  In my opinion, we could solve it by proving that $\forall n\in \mathbb N,a(n)\in \mathbb N$ according to mathematcial induction.  The property P(n) is:$$\forall n\in \mathbb N, a(n)\;is\;unique$$ P(0) is true. And if P(n) holds, P(n++) is true because different natural numbers must have different successors. $$a(n++)=f(n,a(n))$$ $$a(m++)=f(m,a(m))$$ $$n++=m++\Rightarrow n=m\Rightarrow a(n++)=a(m++)$$ It's similar to the proof of  Proposition 2.1.16 (Recursive definitions): Suppose for each natural number $n$, we have some function $f_{n} : \mathbb{N} \rightarrow \mathbb{N}$ from the natural numbers to the natural numbers. Let $c$ be a natural number. Then we can assign a unique natural number $a_{n}$ to each natural number $n$, such that $a_{0} = c$ and $a_{n{++}} = f_{n} (a_{n})$ for each natural number $n$.  This proof indicates both the existence and uniqueness of the function $a$. I don't know why Tao says it's informal.  But regarding the hint, how do we get the function f even if we've got the conclusion from the hint. Also it seems like the function a(n) can be diffentent considering different N. I don't know if the hint is correct. find $\sum_{k=2}^{\infty}\frac{1}{k^2-1}$ Produce an explicit bijection between rationals and naturals? Why do backgrounded processes sometimes stop spontaneously? Sometimes, some time after I've backgrounded a process with bg in bash, when I press Enter in the same shell to redisplay the prompt (just to check that I'm still in bash when some output from the background process has been displayed), the background process seems to stop spontaneously.  If I do bg again the same problem recurs.  The only way to fix it seems to be fg.  Why does this happen? Conjugating verbs for nouns referring to groups of people Possible Duplicate:          Frequently when reading tech articles, I see sentences like "Microsoft have released ..." or "Apple have announced ...". This seems wrong to me because the nouns are singular; Microsoft and Apple are individual companies, even though they refer to groups of people. I have not seen this usage outside of tech journalism, but it's pervasive enough that it makes me wonder: is this actually the correct usage?  As a follow-up question, is it correct to use a plural pronoun for a singular antecedent like this? For example, "Apple has announced they are changing their name to Orange" or "Apple has announced it is changing its name to Orange". The second form seems technically correct but sounds awkward. I can understand this requirement for the old PPC RISC systems and even for x86-64, but for the old tried-and-true x86? In this case, the stack needs to be aligned on 4 byte boundaries only. Yes, some of the MMX/SSE instructions require 16byte alignments, but if that is a requirement of the callee, then it should ensure the alignments are correct. Why burden every caller with this extra requirement? This can actually cause some drops in performance because every call-site must manage this requirement. Am I missing something? Update: After some more investigation into this and some consultation with some internal colleagues, I have some theories about this:  Consistency between the PPC, x86, and x64 version of the OS It seems that the GCC codegen now consistently does a sub esp,xxx and then &quot;mov&quot;s the data onto the stack rather than simply doing a &quot;push&quot; instruction. This could actually be faster on some hardware. While this does complicate the call sites a little, there is very little extra overhead when using the default &quot;cdecl&quot; convention where the caller cleans up the stack.  The issue I have with the last item, is that for calling conventions that rely on the callee cleaning the stack, the above requirements really &quot;uglifies&quot; the codegen. For instance, what some compiler decided to implement a faster register-based calling style for its own internal use (ie any code that isn't intended to be called from other languages or sources)? This stack-alignment thing could negate some of the performance gains achieved by passing some parameters in registers. Update: So far the only real answers have been consistency, but to me that's a bit too easy of an answer. I have well over 20 years experience with the x86 architecture and if consistency, not performance, or something else concrete, is really the reason then I respectfully suggest that is a bit naive for the developers to require it. They're ignoring nearly three decades of tools and support. Especially if they're expecting tools vendors to quickly and easily adapt their tools for their platform (maybe not... it is Apple...) without having to jump through several seemingly unnecessary hoops. I'll give this topic another day or so then close it... Related Is it possible to set DNS for mobile network I have been struggling for one hour with this simple problem (QGIS 1.8.0-Lisboa, Windows 7) :  I have a raster layer. I would like to display the label and not only the band value when I use the Identify Features button. Is it possible? This story was in one of the first SF anthologies I ever read, in the mid-1960s. A meteor lands near to a house. The householder finds it and carries it into his house (meteor is grapefruit/football sized). It’s actually a crashed spaceship, crewed by beings the size of beetles or cockroaches. They emerge, and are spotted by the householder, who of course thinks they’re insects, but notices one seems to be holding a tiny tube. He reaches towards it and the alien shoots his hand (the tube being a gun, of course), stinging him. I can’t recall how the story ends, but I’d love to know what the story was called, and who its author was, as I’m trying to assemble a list of the early SF that fired my enthusiasm for the genre. Is sudo required for installing VMware Tools? I'm trying to install VMware Tools in Ubuntu 16.04. Should I do this by using sudo? Why? When reviewing Suggested Edits on Stack Overflow, I often come across "fixed formatting" suggestions that use  to place emphasis on certain keywords, but isn't actual code.  For example:     I am having a difficult time with a background task in iOS. The problem I seem to be facing is that iOS is silently terminating the App if my background task runs for too long. What can I do to increase time iOS will wait for my background task to complete?   Gets edited to:     I am having a difficult time with a background task in iOS. The problem I seem to be facing is that iOS is silently terminating the App if my background task runs for too long. What can I do to increase time iOS will wait for my background task to complete?   This seems like an invalid use of an inline code span because, well, it isn't code, and it is distracting. There are a    of these edits being made. Often enough they get approved, which reinforces the behavior.  Is this a valid use of inline code spans? If not, should it be edited and corrected? Should edits suggesting these changes be rejected? The usual example of unitary ring without the  property is the ring of column finite matrices, and in this case we have $R\simeq R^2$ as (left) $R$-modules. (See also .) In particular, we have $R^2\simeq R^3$.      I wonder if there is an example of unitary ring (without the IBN property) such that $R^2\simeq R^3$, but $R\not\simeq R^2$ (as $R$-modules).