If $gHg^{-1} \subset H$, must we have $g^{-1}Hg \subset H$?
Conjugate subgroup strictly contained in the initial subgroup?
So basically as it stands I have a laptop which has no cd/dvd drive, and I don't have a usb drive.  The laptop has windows 7 installed with ubuntu 11.04 installed through wubi.  What I want to do is remove windows completely, and make ubuntu the only OS installed on the system.  Is there a way to do this without re-installing ubuntu? (i.e. can I take my wubi install away from windows?)  or is there a way to from inside ubuntu have it run the ubuntu iso somehow so I can just wipe the system and install it fresh? (even if it means I need to have an e.g. 2gb partition just for the image to reside in). Is the ideal $I = \{f\mid f (0) = 0\}$ in the ring $C [0, 1]$ of all continuous real valued functions on $[0, 1]$ a maximal ideal? Is the ideal $I = \{f \mid f (0) = 0\}$ in the ring $C [0, 1]$ of all continuous real valued functions on the interval $[0, 1]$ a maximal ideal? Are there any rulesets or laws for Q or Q continuum? Anything, that would prevent them from doing... anything? Or at least limit them from doing something really bad?  In "" episode Q explains to  that they can do, have, get, become anything they want or appear anywhere they want, with just a snap of fingers. If that is true and if there are absolutely no borders or limits, they can't pass, then how can universe work in general? Or, how did it manage to exist so far?  I mean -- any Q could wipe out Borg, entire human population or even entire universe... with just a snap of fingers. What could prevent Q from doing that? Flowchart using Tikz I'm trying to create a fine flowchart that is a bit complicated. Therefore I need a block for a predefined process and a connector block as well as a data block. Can someone help me? In comment is what I'd like to see in my code to keep my code nicely arranged. The rest of the code is a simple example for the Tikz site.  \documentclass{article}  \usepackage[latin1]{inputenc} \usepackage{tikz} \usetikzlibrary{shapes,arrows} \begin{document} \pagestyle{empty}   % Define block styles \tikzstyle{decision} = [diamond, draw, fill=blue!20,      text width=4.5em, text badly centered, node distance=3cm, inner sep=0pt] \tikzstyle{block} = [rectangle, draw, fill=blue!20,      text width=5em, text centered, rounded corners, minimum height=4em] \tikzstyle{line} = [draw, -latex'] \tikzstyle{cloud} = [draw, ellipse,fill=red!20, node distance=3cm,     minimum height=2em]  %\tikzstyle{subroutine} = [draw,rectangle split, rectangle split         horizontal,rectangle split parts=3,minimum height=1cm]  %\tikzstyle{connector} = [draw,circle,...] %\tikzstyle{data} = [draw, trapezium, ...]  \begin{tikzpicture}[node distance = 2cm, auto]     % Place nodes     \node [block] (init) {initialize model};     \node [cloud, left of=init] (expert) {expert};     \node [cloud, right of=init] (system) {system};     \node [block, below of=init] (identify) {identify candidate models};     \node [block, below of=identify] (evaluate) {evaluate candidate models};     \node [block, left of=evaluate, node distance=3cm] (update) {update     model};     \node [decision, below of=evaluate] (decide) {is best candidate     better?};     \node [block, below of=decide, node distance=3cm] (stop) {stop};     % Draw edges     \path [line] (init) -- (identify);     \path [line] (identify) -- (evaluate);     \path [line] (evaluate) -- (decide);     \path [line] (decide) -| node [near start] {yes} (update);     \path [line] (update) |- (identify);     \path [line] (decide) -- node {no}(stop);     \path [line,dashed] (expert) -- (init);     \path [line,dashed] (system) -- (init);     \path [line,dashed] (system) |- (evaluate); \end{tikzpicture}   \end{document} Should I delete my own questions with answers? I don't know much about this,  But I've some of the questions on which some user has answered (not helpful answer) also but I want to delete those questions, but whenever I go to delete that question. It is prompting with     What does it mean? Can someone tell me what would be the action taken by Stack Exchange if I delete more questions? More Efficient Spatial join in Python without QGIS, ArcGIS, PostGIS, etc I'm attempting to do a spatial join much like the example here: . However, that approach seems really inefficient / slow. Even running this with a modest 250 points takes almost 2 minutes and it fails entirely on shapefiles with > 1,000 points. Is there a better approach? I'd like to do this entirely in Python without using ArcGIS, QGIS, etc.  I'd also be interested to know if it's possible to SUM attributes (i.e. population) of all the points that fall within a polygon and join that quantity to the polygon shapefile.       Here is the code I'm trying to convert. I get an error on line 9:  poly['properties']['score'] += point['properties']['score']   which says:     TypeError: unsupported operand type(s) for +=: 'NoneType' and 'float'.    If I replace the "+=" with "=" it runs fine but that doesn't sum the fields. I've also tried making these as integers but that fails as well.  with fiona.open(poly_shp, 'r') as n:    with fiona.open(point_shp,'r') as s:     outSchema = {'geometry': 'Polygon','properties':{'region':'str','score':'float'}}     with fiona.open (out_shp, 'w', 'ESRI Shapefile', outSchema, crs) as output:         for point in s:             for poly in n:                 if shape(point['geometry']).within(shape(poly['geometry'])):                       poly['properties']['score']) += point['properties']['score'])                     output.write({                         'properties':{                             'region':poly['properties']['NAME'],                             'score':poly['properties']['score']},                         'geometry':poly['geometry']}) Get string inside parentheses, removing parentheses, with regex Alternate Row Coloring in Django Template with More Than One Set of Rows Django templates offer the builtin tag cycle for alternating between several values at different points in a template (or for loop in a template) but this tag does not reset when it is accessed in a scope outside of the cycles definition.  I.e., if you have two or more lists in your template, the rows of all of which you'd like to use some css definitions odd and even, the first row of a list will pick up where the last left off, not with a fresh iteration from the choices (odd and even)  E.g., in the following code, if the first blog has an odd number of entries, then the first entry in a second blog will start as even, when I want it to start at odd.  {% for blog in blogs %}   {% for entry in blog.entries %}     &lt;div class="{% cycle 'odd' 'even' %}" id="{{entry.id}}"&gt;       {{entry.text}}     &lt;/div&gt;   {% endfor %} {% endfor %}   I've tried obviating this by patching with the resetcycle tag offered here:    to no avail.  (The code didn't work for me.)  I've also tried moving my inner loop into a custom tag, but this also did not work, perhaps because the compile/render cycle moves the loop back into the outer loop?  (Regardless of why, it didn't work for me.)  How can I accomplish this simple task!?  I'd prefer not to create a data structure in my view with this information pre-compiled; that seems unnecessary.  Thanks in advance. How to install Ubuntu 16.10 without any gui? I want to start my computer and it should open up to a CLI. I don't want a GUI, no fancy login screen etc.  I need a solution that does not use a minimal ISO because it requires an internet connection. I need an offline installation. dpkg exit with error parsing file `/var/lib/dpkg/status`, what to do? When I try to install any software, I encounter this error, and therefore I cannot update.  Preconfiguring packages ... dpkg: error: parsing file '/var/lib/dpkg/status' near line 51245 package 'oracle-xe':  mixed non-coinstallable and coinstallable package instances present N: Ignoring file 'gcl' in directory '/etc/apt/sources.list.d/' as it has no filename extension N: Ignoring file 'gcl' in directory '/etc/apt/sources.list.d/' as it has no filename extension E: Sub-process /usr/bin/dpkg returned an error code (2) Which comes first: cat or dog? Which comes first in a sentence?  I know some word pairs such as bacon and eggs, where bacon always comes first. E.g:     Make me bacon and eggs for dinner, honey.   Cats and dogs are the two most common pets I know of. What is the preferred order?   Dogs are superior.     Don't put dogs and cats together, they might fight!  Cats are superior.     Don't put cats and dogs together, they might fight! Why is variance squared? The mean absolute deviation is:   $$\dfrac{\sum_{i=1}^{n}|x_i-\bar x|}{n}$$   The variance is: $$\dfrac{\sum_{i=1}^{n}(x_i-\bar x)^2}{n-1}$$   So the mean deviation and the variance are measuring the same thing, yet variance requires squaring the difference. Why? Squaring always gives a non-negative value, but the absolute value is also a non-negative value. Why isn't it $|x_i-\bar x|^2$, then? Squaring just enlarges, why do we need to do this?  A similar question is , but mine is a little different. Thanks. What's the simplest SQL statement that will return the duplicate values for a given column and the count of their occurrences in an Oracle database table?  For example: I have a JOBS table with the column JOB_NUMBER.  How can I find out if I have any duplicate JOB_NUMBERs, and how many times they're duplicated? I want to use the top half of the circle to make a cut but whenever I apply the boolean modifier, the circle just stays there and becomes attached to my other object.  I've managed to make the cut in a standard cube but not sure why it's not working for this...? Does an Action Surge grant a second bonus action? We were trying to understand how the "Action Surge" rule works, and after some discussion we came to a standstill.      Starting at 2nd level, you can push yourself beyond your normal limits for a moment. On your turn, you can take one additional action on top of your regular action and a possible bonus action   The keyword "possible" is what threw us off. Half the group thought it meant "additional action or bonus action", and the other half thought it was "additional action and bonus action".  So which is it? Human-readable filesize with find's printf Sum of principal minors Proving there is a sequence convergent to a limit point of a set without axiom of countable choice? Often, we use a construction like this: Given a subset $ A $ of a metric space and its limit point $ a $, we know that for every $ \epsilon &gt; 0 $ there is another point $ x $  different from $ a $ such that $ d(x,a) &lt; \epsilon $. So for every natural $ n $ we let $ a_n $ be such a point within $ 1/n $ of $ a $, which gives us a sequence convergent to $ a $.  My question is, is the axiom of countable choice needed for this construction, or is it formally correct just in ZF? Subsample of a random sample: random sample? Choice of personal pronoun in single-author papers