php explode all characters
PHP: Split string into array, like explode with no delimiter
Using Squeeze Theorem to show the following limits Consider a function f (x) defined on R satisfying:   for all x distinct 0.  Calculate: lim f(x) with x→∞ and limf(x) with x→−∞   Issue information:   if x → ∞ then we can consider | x | = x  if x → -∞ then we can consider | x | = -x  I can use x² = | x |? No indentation after theorem environment with amsthm I use the amsthm package and dont want lines which start right after the theorem environment to be indented. I consulted the manual of the package and it said to define a new theorem style. I expected the following MWE to accomplish this task.  \documentclass[12pt,a4paper]{scrreprt}  \usepackage{amsthm} \newtheoremstyle{abcd}% name   {}%      Space above, empty = `usual value'   {}%      Space below   {\itshape}% Body font   {}%         Indent amount (empty = no indent, \parindent = para indent)   {\bfseries}% Thm head font   {.}%        Punctuation after thm head   {.5em}% Space after thm head: \newline = linebreak   {}%         Thm head spec \theoremstyle{abcd}  \newtheorem{defn}{Definition} \begin{document} \begin{defn} Some defintion \end{defn} This sentence shouldn't be indented. \end{document}   However, I end up with this   That is what I would expect (obtained using a noindent right after the theorem environment ends) Disable Tabbing in Firefox 3, Chrome 4 and IE8? Tabbed Browsing may be nice for reading news sites in one sitting, but I still think they are a usability nightmare if you need to keep the page open for a long time, e.g., for testing it while developing or as a reference for something.  The nice thing about the Windows Taskbar (before Windows 7 ) is that it's easy and natural to remember where things are. I can have 30 tabs in it, but because I know what each one is, I know where I have to click to open something - it's the most efficient way of working I've encountered so far.  Sadly, Tabbed Browsing completely breaks this efficiency because it is not possible to specifically click on a tab in the taskbar, I have to click on the browser, search the tab and then click it, which means at least 2 clicks.  Long story, short question: Is there an extension or setting to completely disable tabbing on Firefox 3, Chrome 4 and Internet Explorer 8 and have one Window/Taskbar entry for each open page? I know that in Chrome I can just drag a tab out of a Window to create a new one, but if there is a general way, that would be easier.  Edit: IE8 conveniently offers an option for that: Tools - Options - Tabs - Enable Tabbed Browsing. I have a directory that contains the following:  x.pdf y.zip z.mp3 a.pdf   I want to delete all files apart from x.pdf and a.pdf. How do I do this from the terminal? There are no subdirectories so no need for any recursion. Is there a power saving application similar to Jupiter? Fields - Proof that every multiple of zero equals zero This is one of my first proofs about fields. Please feed back and criticise in every way (including style and details).  Let $(F, +, \cdot)$ be a field. Non-trivially, $\textit{associativity}$ implies that any parentheses are meaningless. Therefore, we will not use parentheses. Therefore, we will not use $\textit{associativity}$ explicitly.  By $\textit{identity element}$, $F \ne \emptyset$. Now, let $a \in F$. It remains to prove that $0a = 0$. \begin{equation*} \begin{split} 0a &amp;=  0a +  0      &amp;&amp; \quad \text{by }\textit{identity element }(+    ) \\    &amp;=  0a +  a + -a &amp;&amp; \quad \text{by }\textit{inverse element  }(+    ) \\    &amp;=  0a + 1a + -a &amp;&amp; \quad \text{by }\textit{identity element }(\cdot) \\    &amp;= (0 + 1)a + -a &amp;&amp; \quad \text{by }\textit{distributivity   }        \\    &amp;= (1 + 0)a + -a &amp;&amp; \quad \text{by }\textit{commutativity    }(+    ) \\    &amp;=      1 a + -a &amp;&amp; \quad \text{by }\textit{identity element }(+    ) \\    &amp;=        a + -a &amp;&amp; \quad \text{by }\textit{identity element }(\cdot) \\    &amp;=  0            &amp;&amp; \quad \text{by }\textit{inverse element  }(+    ) \end{split} \end{equation*} QED  PS: Is "Let $(F, +, \cdot)$ be a field." ok? Besides, I would not want to call $F$ a field, because $F$ is just a set. Also, what do you think about using adverbs like "Now"? How would you have said the associativity-thing? Wikipedia entry on likelihood seems ambiguous How to create and animate the water reflection (Caustics) on an object? What is the best method to create this kind of reflection and how to animate it? Is there anything that is totally random? When I say totally random, I mean absolutely random, not pseudorandom. If I want to say "totally random" numbers such as 1,26,17,4,1 and 27, although I see them to be totally random, they aren't. These are numbers that I think are influenced by my childhood, ideology and everything that I've seen. So, what do you think? Is there anything completely random? Can I answer my own questions, even if I knew the answer before asking? I might want to answer my own question because:  I arrived at a solution before there were any other correct answers or I like mine better, can I still answer my own question?  I have a folder with lists of code snippets for things I always forget or get wrong, such as regular expressions for processing XML, common WinForms control idioms, etc. Is it considered poor etiquette for Stack Overflow to ask a question I already know the answer to, and then self answer, just so it gets recorded on the website?   Related:          For more information, see &quot;&quot; in the . 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? If $f \colon [a,b] \rightarrow \mathbb{R}$, then show that there exists $c \in [a,b]$ such that $\int_a^c f = \int_c^b f$ If $f \colon [a,b]\rightarrow \mathbb{R}$, then show that there exists $c \in [a,b]$ such that $c \in [a,b]$ such that $\int_a^c f = \int_c^b f$.  I think that I have to proceed with the Mean Value Theorem of Integrals... How do I install a .tar.gz (or .tar.bz2) file? I have downloaded tar.gz files. But I don't know how to install it. How do I install this kind of file? t-test or z-test: assume normality or s≈σ? Let's say I have a large sample ($n&gt;30$) with mean $\bar{X}$ and standard deviation $S$. I can calculate only: $T=\frac{\bar{X}-\mu}{S/\sqrt{n}}$.  If I want to use t-test for a hypothesis, then I have to assume normality of the population. If I want to use z-test for a hypothesis, then I have to assume that $\boldsymbol{s\approx\sigma}$.  What is the less important assumption? What test should I do? Should I do t-test, z-test or doesn't matter? Determine app that keeps turning on bluetooth installing rtl8814AU wifi adapter driver on ubuntu 16.04 The reasoning my book uses is as follows:   Since $(3+i)(3-i) = 10$, $10 + \langle 3+i\rangle = 0 + \langle 3+i\rangle $. Also, $i + \langle 3+i\rangle = -3 + \langle 3+i\rangle = 7 + \langle 3+i\rangle$. So, $\mathbb{Z}[i]/\langle 3+i\rangle = \{k + \langle 3+i\rangle \mid k = 0,1,\ldots ,9\}$, since $1 + \langle3+i\rangle$ has additive order $10$.   I do not understand why the additive order of $1 + \langle 3+i\rangle$ is $10$, or why the fact that $(3+i)(3-i) = 10$, shows the additive order or $1 + \langle 3+i\rangle$  is $10$. If someone could please explain this I would greatly appreciate it.   Note: I apologize for not using MathJax to write this post. I intend to learn it over the coming weekend. given that $f$ is an analytic function with real part $u$ is a polynomial in the variable of $x,y$, $z=x+iy$, we need to show $f$ is a polynomial in $z$, I am kind of puzzled to see the problem, first I would like to say:any hint please Non-hidden directory doesn't show in Explorer, but the program that made it can access it Solving $x - a \log(x)=b$ Let $a&gt;0$ and $b \in \mathbb{R}$: Assume there exists an $x &gt;0 $ s.t. $$x - a\log(x) = b$$ holds. How can it be determined in closed-form?