I am looking to replace the \qed or \qedsymbol with a Christmas tree or a Christmas tree inside a box. I've done this already with a smiley by using \renewcommand{\qedsymbol}{\smiley}, but I don't know how one would go about this using a Christmas tree (since there is no Christmas tree character)
I'm trying to find an alternative to the standard tombstone qed symbol for more informal papers. I initially thought of an empty square with Pub written inside, but what would actually be better would be a small beer mug symbol. (much like the one found in this set of icons )  Unfortunately there doesn't seem to such a symbol in the comprehensive latex symbol list (although many funny symbols can be found there). Has anyone thought about this? Is there any quick-and-dirty solution?
Schwarz's Lemma, fixed points question Show that $\frac{(2n)!!}{(2n+1)!!}$ converges. I work with QGIS 2.10.1 on Windows 7 (x64). I have dissolved polygons from an attribute value and the polygons geometries being not perfectly joined together, I get some 'garbage' nodes I need to delete. I have tried to edit the layer and using nodes tool, selecting and deleting the nodes, but it seems impossible to do (nodes are not deleted at all!). Any idea on how to process this kind of clean-up?  EDIT : you can  for testing. Custom arrangement for fields with multiple values in Drupal 7 Labels disappear while zooming changing notification emails from WordPress @mydomain.net to something else How do I change notification emails address from WordPress @mydomain.net to something else.  I want to do this because WordPress @mydomain.net ends up getting flagged as junk mail.  Thanks  Daniel How to export a individual layer with a fixed master layer in Photoshop? Let's say I have some layers and a single different one, or a group of layers I want to export merged together, in a way that every single exported layer is merged with a specific layer or group of layers.  In the example below I have some layers which need to be exported into JPG or PNG, merged with the very top layer called "Blurred". In my case, I want to export the layers (Jan 8 + Blurred) and (Layer 10 + Blurred) and so on. Acting as exporting layers merged with a master layer called "Blurred".  My question in a simple way: how to apply a Master layer(s)/Group(s) in Photoshop to be exported with every layer I have? If $f(xy)=f(x)f(y)$ then show that $f(x) = x^t$ for some t "Neither", "none", "no one" + [of them] + verb-s In a comment on English Language &amp; Usage I read the following answer responding to a(n) asker's question: &quot;Neither sound natural.&quot; I have always had more than one doubt on the &quot;neither&quot; usage and I would like understand(ing) the &quot;secrets&quot; to use this word better or, at the best, correctly. So, let us consider the following examples:  1 Neither sound natural. 2 None sound natural. 3 No one sound natural. 4 Neither of them sound natural. 5 None of them sound natural. 6 No one of them sound natural. 7 Neither sounds natural. 8 None sounds natural. 9 No one sounds natural. 10 Neither of them sounds natural. 11 None of them sounds natural. 12 No one of them sounds natural.  Comparing the above sentences (one) with each other, can anybody explain which is grammatical and why? Quantum levitation, flux pinning -- basically, when a superconductor floats above a permanent magnet, is really fascinating. But does the strength of the magnetic field influence the superconductor's height? And what relationship/formula suggests this?  For example, if I had a coil wrapped around a metal object and then ran a small current through it, a small magnetic field would be generated and a superconductor exposed to it would float about it at some height that I put it on.  But what if I increased the current, so that the magnetic field also increased? What happens to the superconductor? Does its height change? Or does it just get harder to "pull out" of its levitating state? In his  Feynman calculates the field momentum of a moving charged sphere with charge $q$, radius $a$ and velocity $\mathbf{v}$. He finds that the total momentum in the electromagnetic field around the charged sphere is given by:  $$\mathbf{p} = \frac{2}{3} \frac{q^2}{4\pi \epsilon_0} \frac{\mathbf{v}}{ac^2}.$$  He calls the coefficient between the field momentum, $\mathbf{p}$, and the velocity, $\mathbf{v}$, the electromagnetic mass:  $$m_\textrm{elec}=\frac{2}{3} \frac{q^2}{4\pi \epsilon_0 a c^2}.$$  He claims that this electromagnetic mass $m_\textrm{elec}$ has to be added to the standard "mechanical mass" of the sphere to give the total observed mass of the object.  Would this view be accepted by most physicists today?  Have any experiments been performed that show the effect of the additional electromagnetic mass on the dynamics of a macroscopic charged object?  I guess the problem is that such an effect would only be large enough to be observable for charged particles like electrons. In that case it would be difficult to distinguish mechanical mass, presumably due to the Higgs field, from electromagnetic mass. Maybe one could perform a high energy/short length scale experiment on an electron that excluded the effect of the electromagnetic mass? I changed both the desktop and login screen background photos. However,only desktop photo is changed. The one on the login screen is still the purple Ubuntu one. Is this a bug? Calculate work done by a hovering helicopter over time This is likely to be very simple, but...  How does one calculate work done by a hovering unmoving aircraft over time?  As in work in Joules.  In this scenario, to remain hovering the aircraft has to exert a force that counters gravity (which would be its mass times G, pointing in opposite direction of gravitational pull).  However, work is defined as newton per meter, and the aircraft does not move.  Meanwhile the battery charge or fuel is going to be expended, so the energy is spent.  The other question here:   is dealing with conservation energy and not calculating drain/work performed by hovering. How do I simulate in Photoshop what a piece will look like when printed on non-white paper? I'm designing a box in Photoshop that will be offset printed on unbleached paper. I haven't picked out a printer yet, so I don't know the exact kind of paper I'll be using and don't have access to it for proofs. For now I'm using a lightly-textured layer of tan color as a placeholder to mock it up.  What I'm trying to figure out is, how do I figure out how my design will look printed on natural paper rather than bleached white paper? I know that the brightness will be diminished and the hue will be altered, but I need to know how much so I can compensate for it as much as possible.  Is there a way to get at least a rough but reliably-simulated idea of how my prints will come out? Does it have to do with blend modes, or color separations? I'm at a bit of a loss here. Applying for tourist visa for US in country other than your own Possible Duplicate:          Can British passport holders apply for a B2 USA visa from other countries, if they are living there? Or do they have to go back to Britain to apply for it? A gold reviewer badge? For your continued efforts in reviewing posts, even though the system sometimes messes up and doesn't let you actually review things and keeps displaying them over and over and over. So also, for your patience in putting up with the glitches in the review panel too! Haha  Anyways, a gold reviewer badge: 20000 reviews, over 4000 actioned  I just multiplied both numbers by 20. Think those numbers seem challenging? Is anyone up near those numbers or should it be multiplied by 10 instead? I prefer the higher amount because it would be gold and something harder to work for. :) But we also have to consider the longevity of when all these posts are eventually reviewed and it's only new posts being created.  Anyways, my stats for those who are interested (I wouldn't get the badge to start because I only have ~2000 actioned):  Upvoted            189 Downvoted          11 Edited             926 Commented          127 Voted to Close     44 Flagged            447 Reviewed           21609   As far as the name of the badge, I really like "The Owl is Watching" but not sure if that would be too long. Sounds snazzy though. Ideas?    Personally, I was on a quest to try and clear out all the posts in a single tab before it started showing me the same things over and over (and over) and then it got frustrating because I wasn't even making progress. Quest denied. :(    Lately I've noticed a massive build-up of unreviewed posts. When the review panel was first implemented, there would only ever be maybe 50 unreviewed posts at a time (in a given tab) for my monthly view. Now I log in and there's a thousand or two thousand pending. I think a lot of people quit reviewing after the first badge, so having a gold badge with a high threshold would really improve activity in the review panel and keep people going to improve the community. Possible to do a MySQL foreign key to one of two possible tables? Well here's my problem I have three tables; regions, countries, states.  Countries can be inside of regions, states can be inside of regions.  Regions are the top of the food chain.  Now I'm adding a popular_areas table with two columns; region_id and popular_place_id.  Is it possible to make popular_place_id be a foreign key to either countries OR states.  I'm probably going to have to add a popular_place_type column to determine whether the id is describing a country or state either way. Why are pointers such a leading factor of confusion for many new, and even old, college level students in C or C++?  Are there any tools or thought processes that helped you understand how pointers work at the variable, function, and beyond level?  What are some good practice things that can be done to bring somebody to the level of, "Ah-hah, I got it," without getting them bogged down in the overall concept? Basically, drill like scenarios. Every element outside the maximal ideal of a local ring is a unit A homework question from my algebra class asks:     Show that in a local ring $R$ with maximal ideal $M$, every element outside $M$ is a unit.   My argument is that since $M$ is maximal $R /M $ is a field and so for any $ x \in R \backslash M $, $ x + M $ has a multiplicative inverse, which implies $ x $ is a unit.  I don't see where we need the fact that $R$ is a local ring. I have a mesh and in the region around each triangle, I want to compute an estimate of the principal curvature directions. I have never done this sort of thing before and  does not help a lot. Can you describe or point me to a simple algorithm that can help me compute this estimate?  Assume that I know positions and normals of all vertices.