I find a lot of questions, particularly on SO, with no answer but a long trail of comments which once read, it becomes apparent it has been answered. Often with a comment by the OP saying something like "thanks that worked". It makes it a much longer search when looking for an answer.    Posting an answer which covers the content of the comments is considered a good practice, but OP seem disinclined to do (refer  )  To encourage OP behavour my proposal is to specifically give OP rep if they post the answer to their question when its    resolved with no other answers in order to complete the    documentation.  I trust I am not asking something that already has an established approach.
This has been , but a long time ago, and got closed for a rather confusing reason (converting comments to answers is not an "exact duplicate" of converting answers to comments), so I'm going to bring it up again.  I think it makes sense to have a user (not asker) option to convert a comment they posted on a question to an answer on the question, if it turns out it led to the asker figuring out the answer. We've all seen askers reply to comments with "@foo Hey, that was it! Post that as an answer and I'll accept it"; why not make it simple for the user to do that? It seems trivial to implement, and there's no formatting issues like there is going from answers to questions. I'm not sure how it could be "abused", because you need less rep to answer a question than to comment on it. I don't know if the answer's post time should be the time of the comment or the time it was converted; I think probably the latter. I also don't know if the comment should be deleted, left alone, or replaced with a link to the answer; again I think probably the last
propositional calculus problem, how to prove this right or wrong? $A$$\rightarrow$$(B$ $\vee$ $C$ ) , $B$ $\rightarrow$ $C$ $\vDash$ $A$ $\rightarrow$ $D$  I think it's wrong but I have no idea how to prove. Send values from one form to another form Is this valid for convergence? Does $\sum_{n=1}^{\infty} \sqrt[n]{3} - 1$ converge or diverge?   Hints please  I have that $0 \le \sqrt[n]{3}  - 1 \le 1$  Does this help? Is it possible to get a list of most recently installed packages? Import a module from a relative path Recently I booked a flight using my points. I am  planning to fly to Seattle WA from Indianapolis Indiana.  Stop over is Chicago.  On the day of my flight I am supposed to be in Chicago.   So I was wondering if I can directly board my Seattle flight from Chicago thereby not showing up in Indianapolis.  Is this okay?  Will United airlines cancel my entire journey if I do not show up in Indianapolis? Do any (non-hardware) RNGs exist which could be used to create an OTP for crypto purposes? Filtered Review Queue doesn't show any audits Simple enough question: is there some shell command (or GUI method) I can use that, given the path to a file on my system, tells me what package put it there? Assuming the file did in fact come from a package, that is.  Bonus question: what if it's a file that isn't installed on my system? Is there, say, a website that will let me look up a file and see what packages, if any, provide it? Is it possible to recover an account deleted at the SE team level? Teleporting a player from the overworld to the end Is there any way to teleport a player from the overworld to the end?   Or a way of teleporting a player to a random enderman in the end? Can more than one antibody bind the same antigen I'd like to clear something up about antibodies that I'm not sure I've understood in the articles I've read. Looking at concepts such as "affinity maturation", "monovalent antigens" and "polyvalent antigens" it seems as if there are multiple antibodies which can bind to the same antigen. (Although I think I'm right in saying that individual antibodies can only bind to one antigen?) However, when I read sentences like "It has been estimated that humans generate about 10 billion different antibodies, each capable of binding a distinct epitope of an antigen" on the Wikipedia page (for antibody) it does make it sound like it's one antibody per antigen? Is this the case? Or is it one antibody per epitope. Either way, to put this question in a nutshell:  Is it true to say that the same substance could bind with (and, therefore, be recognised by) more than one antibody, or not?  Also, if the answer is no, does that mean that antibodies with different binding affinities are classed as the same antibody or not? I am technically knowledgeable enough to know that this most likely isn't possible, BUT, I am curious just the same (it must be put to rest). Is there anything preventing us from creating a means to use two different internet connections, like two different ethernet cards or an ethernet card and a wireless card, and using the two IP addresses at once for more internet speed?  My specific situation is that I would like to use both a wireless card and my wired connection on my machine running Kubuntu 13.10. Using two internet connections would allow me to do things like:   Torrent and browse simultaneously without lag Open Firefox with multiple tabs faster (?) Download a couple or a few large files at once double time Increase overall internet connection speed (?) Parametric vs non-parametric machine learning methods I looked-up many references and websites and researched on how to determine if a method is between parametric or non-parametric. I came up with below definitions,     A parametric algorithm has a fixed number of parameters. In contrast, a non-parametric algorithm uses a flexible number of parameters, and the number of parameters often grows as it learns from more data.   From .  Moreover, I found,     A parametric model, we have a finite number of parameters, and in nonparametric models, the number of parameters is (potentially) infinite.    From .  And many other methods of determination, though the problem is none of them can helo ones to determine if a certain hypothetical method is parametric or not. (For instance, why k-means' number of parameters are constant but KNN is variable or basically what do we call a parameter and what we do not?) Can a sequence which decays more slowly still yield a converging series? In Bergman's companion notes to Rudin, he says that "If a sequence of positive terms has convergent sum, so does every sequence of positive terms which decays more rapidly." So given a sequence $\{a_n\}$ of positive terms such that $\sum_n a_n$ converges, if $\{b_n\}$ is such that $$ \lim_{n\to\infty} \frac{a_n}{b_n} = +\infty, $$ then $\sum_nb_n$ converges. I can prove this given $\{a_n\}$ and $\{b_n\}$. However, can we find $b_n$ which decays more slowly, i.e. $$ \lim_{n\to\infty} \frac{b_n}{a_n} = +\infty $$ such that $\sum_n b_n$ converges?  Similarly, we have the claim "if a sequence of positive terms has divergent sum, then so does every sequence of positive terms which decays more slowly." How can I vertically align the numerators of two fractions? I just saw a user named: .yahoo.co.jpaqwsykcj3aulh3h1k0cy6nzs3isj  Could new users be named according to their user-number, or something other than "Unknown"? Perhaps User1234567 instead? It would be less awkward to address them in answers and comments.   Additionally, I often times have to check profiles to make sure users aren't abusing the system, since I find many of the same questions from "unknown (google)" from time to time. That, or I'll mistakenly think I've helped the user on a similar issue in the past, and assume the user has knowledge that he or she does not have. For simple linear regression, the regression coefficient is calculable directly from the variance-covariance matrix $C$, by  $$ C_{d, e}\over C_{e,e} $$ where $d$ is the dependent variable's index, and $e$ is the explanatory variable's index.  If one only has the covariance matrix, is it possible to calculate the coefficients for a model with multiple explanatory variables?   ETA: For two explanatory variables, it appears that $$\beta_1 = \frac{Cov(y,x_1)var(x_2) - Cov(y,x_2)Cov(x_1,x_2)}{var(x_1)var(x_2) - Cov(x_1,x_2)^2} $$ and analogously for $\beta_2$. I'm not immediately seeing how to extend this to three or more variables. Are groups satisfying $g=g^{-1}$ for all $g \in G$ abelian? Is the following statement true or false:  If $G$ is a group with the property that $g=g^{-1}$ for all $g \in G$, then $G$ is abelian.   I believe it is false since I know that abelian or commutative property implies that every element in $G$ must have an inverse. Thus $g\cdot g^{-1}= g^{1}\cdot g = e$. I need someone to check my attempt. How to justify $\phi(n) \ge \sqrt{n}$ If $\phi(n)$ is the Euler-totient function, how can I show that $\phi(n) \ge \sqrt{n}$?