How do I 'unfavorite' a deleted room?
How to remove deleted chatroom from favorite rooms?
Disable back button in android Discontinuous derivative. Could someone give an example of a ‘very’ discontinuous derivative? I myself can only come up with examples where the derivative is discontinuous at only one point. I am assuming the function is real-valued and defined on a bounded interval. What is the name of this Ubuntu program? A couple month ago I installed a bunch of clipboard manager programs in Ubuntu, tried them out and then removed them. I must have missed one of these and now it keeps bug me in my daily usage. I need some help to identify the name of this program because the program itself provides very limited information.  This clipboard program has below characteristics: 1. It occupies hotkey Ctrl+;. When I press this hotkey, the clipboard history will pop out. It happens in bash, Chrome, Eclipse IDE, and etc, wherever it is text inputable. This is kind of annoying because it overrides my other hotkeys inside these applications. 2. Very laconic UI. Like below picture, with only a line "Select to paste", then listing out the clipboard history. There is no program information whatsoever. Right clicking on it and no menu are shown at all.      So far I have tried below ways to identify this program: 1. Browse system monitor for processes with names that could be correlated. 2. Browse through my installation log (dpkg.log) to find my installation history. Without luck, the log is lost. But I was not successful. I often get an error saying      unable to update ICE authority.    Is there a way out of this? Why is time special? In Special Relativity, the spacetime interval between two events is $s^2 = -(c{\Delta}t)^2+({\Delta}x)^2+({\Delta}y)^2+({\Delta}z)^2$ giving the Minkowski metric $\eta_{\mu\nu}=\text{diag}(-1, 1, 1, 1)$. What is the justification for making time have a negative coefficient, and how closely is that related to the 2nd law of thermodynamics? Sure, by letting $\eta = \text{diag}(1, 1, 1, 1)$, we get a pretty boring spacetime, and the boosts in the Poincaré group become trig instead of hyperbolic functions, but what's the physical reasoning behind this? How do you construct a std::string with an embedded null? If I want to construct a std::string with a line like:  std::string my_string("a\0b");   Where i want to have three characters in the resulting string (a, null, b), I only get one.  What is the proper syntax? How to modify the space between the numbers and text of sectioning titles in the table of contents? I'm preparing a document using the book class. In the table of contents, the space between the subsection number and title is too wide. How to reduce it? When will "Present Perfect vs. Past Tense" cases be affected by culture? Regarding actions taken in the past, besides the differences those two tenses have semantically, my teacher shared that it could be a British vs American English case.   When talking about past action, British prefers present perfect because they take into account that the effect from their past action still happens until now. As for American, they prefer to state the action only. It happened in the past, so past tense it is.     I have had dinner. [British]   vs.      I had dinner. [American]   I hope to hear it from the native speakers, both British and American. What do you think about this? Is it true?  If it is, I don't think it can apply to all cases of past actions. There have to be cases when both style agree to use the same tenses. Could you please help me define the situation when this kind of difference applies and when doesn't? WinForms Global Exception Handling? Just don't show UI for actions that can't be actioned Recently I just deleted one of my answer in stackoverflow where there was one comment. After deleting the answer it also show for sometime that we all know but in the comment it still allow us to up to make it useful but as I clicked it it just showed me the message:  If we are not allowed to do then what was the meaning? Why don't it just be removed or make it disable if the answer is deleted. Just don't show UI for actions that can't be actioned When is a gerund supposed to be preceded by a possessive adjective/determiner? Can a probability distribution value exceeding 1 be OK? On the , there is this line:      $p(\mathrm{height}|\mathrm{male}) = 1.5789$ (A probability distribution over 1 is OK. It is the area under the bell curve that is equal to 1.)    How can a value $&gt;1$ be OK? I thought all probability values were expressed in the range $0 \leq p \leq 1$. Furthermore, given that it is possible to have such a value, how is that value obtained in the example shown on the page? Show that the Sorgenfrey line does not have a countable basis. I am trying to understand this proof from Munkres' book which shows that the Sorgenfrey line does not have a countable basis. His proof is:  Let $\beta$ be a basis for $\mathbb{R}_l$. Choose for each $x$ an element $B_x \in \beta$ such that $x \in B_x \subset [x, x+1)$. If $y$ is not equal to $x$ then $B_y \neq B_x$ since inf($B_x$) = $x$ and $y$ = inf($B_y$). Therefore $\beta$ must be uncountable.   I am new to topology so I am probably just missing a simple point but I do not see why $\beta$ must be uncountable according to this argument. I agree that $B_y \neq B_x$ but isn't it possible that $y \in B_x$ (and thus the set $B_y$ is not needed as part of the basis)? Thanks in advance for your help. What determines the direction of precession of a gyroscope? I understand how torque mathematically causes a change to the direction of angular momentum, thus precessing the .  However, the direction, either clockwise or counterclockwise, of this precession seems to me a bit arbitrary beyond mathematical definitions. (What if torque were defined by a "left hand rule", for example?).  What's the fundamental physical reason that the precession of a gyroscope would be directed in a certain direction? Zooming to WMS layer after CQL filter in OpenLayers? I created a layer that contains points and I added it to a map as WMS layer in OpenLayers. I did a CQL filter and it works but I'd like to zoom to the selected point when I worked with getextent or getdataextent it doesn't zoom to the right place. It missed with a few Km. Here is my the code of filter:   function filterNom(){             var filterType ="cql";             var filter = document.getElementById('batima').value;             // by default, reset all filters             var filterParams = {cql_filter: null};             if (OpenLayers.String.trim(filter) != "") {                 if (filterType == "cql")                      filterParams["cql_filter"] = "batiment='"+filter+"'";              }             // merge the new filter definitions             wfs_layer.mergeNewParams(filterParams);             var bounds =  new OpenLayers.Bounds             bounds = wfs_layer.getExtent()             map.setCenter(wfs_layer.getExtent(),18);             var center = map.getCenter();             center.transform(new OpenLayers.Projection("EPSG:4326"), new OpenLayers.Projection("EPSG:900913"));             alert(center.toString()); }   and here is the code to add the WMS layer:    wfs_layer = new OpenLayers.Layer.WMS("Patrimoines",         "http:// localhost/geoserver/cite/wms",          {layers: 'cite:patrimoine' , transparent: true },         {isBaseLayer: false, opacity: 1, singleTile: true, visibility: true,          projection: 'EPSG:900913'}); In my textbook, a relationship is plotted between the resistance of the material and the temperature, and the temperature coefficient is defined as the slope of that graph divided by an arbitrary resistance $R_1$ on the graph. Does that mean that the coefficient varies depending on the temperature I choose to divide the slope by?  If so, how does it stand as a valid reference to the material’s resistance growth rate with temperature?  If not, then where did I go wrong with this train of thought? Solve $\frac1x+\frac1y=\frac1{pq}$ For $x,y\in\mathbb{N}$ how many ordered pairs $\left(x,y\right)$ satisfy   $\dfrac{1}{x}+\dfrac{1}{y}=\dfrac{1}{pq}$ where $p,q$ are distinct primes? Here is a question that's been bothering me since I was a sophomore in university, and should have probably asked before graduating:  In analytic (Lagrangian) mechanics, the derivation of the Euler-Lagrange equations from the principle of least action assumes that the start and end coordinates at the initial and final times are known. As a consequence, any variation on the physical path must vanish at its boundaries. This conveniently cancels out the contributions of the boundary terms after integration by parts, and setting the requirement for minimal action, we obtain the E.L. equations.  This is all nice and dandy, but our intention is finding the location of a particle at a time in the future, which we do not know a priori; after we derive any equations of motion for a system, we solve them by applying initial values instead of boundary conditions.   How are these two approaches consistent? About the number format in ticks limit of Holder norms: $\sup\limits_{x\in [a,b]} f(x) = \lim\limits_{n\rightarrow\infty} \left(\int_a^b (f(x))^n \;dx\right)^{\frac{1}{n}}$