I'm trying to download Heroku for the first time onto my Ubuntu 16.04 and I'm following the Heroku website's instructions exactly by the following:   sudo add-apt-repository "deb https://cli-assets.heroku.com/branches/stable/apt ./" curl -L https://cli-assets.heroku.com/apt/release.key | sudo apt-key add - sudo apt-get update sudo apt-get install heroku   But every time I get to sudo apt-get update I receive the following errors:  W: the repository 'http:''cli-assets.heroku.com/branches/stable/apt ./ Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.  N: See apt-secure(8) manpage for repository creation and user configuration details. E: Failed to fetch http://cli-assets.heroku.com/branches/stable/apt/./Packages 403 Forbidden [IP: 52.84.3.182 80] E: Some index files failed to download. They have been ignore, or old ones used instead. W: Duplicate sources.list entry https://cli-assets.heroku.com/branches/stable/apt ./Release   Suggestions?
I downloaded Heroku from Heroku toolbelt using  wget -qO- https://toolbelt.heroku.com/install-ubuntu.sh | sh   in the terminal, which they recommended on their site.   My Ubuntu (14.04.1) didn't recognize the -q0-, so I took it out.  It then seemed to download fine - I see the  in the directory I was in when i downloaded it.   Now, however, it still doesn't recognize heroku as a command.  It also won't show me where it is with the 'whereis' command.  But when I look in the current directory with ls -a, it shows up.  It seems to be there.   How do I install it?
When to choose checked and unchecked exceptions In Java (or any other language with checked exceptions), when creating your own exception class, how do you decide whether it should be checked or unchecked?  My instinct is to say that a checked exception would be called for in cases where the caller might be able to recover in some productive way, where as an unchecked exception would be more for unrecoverable cases, but I'd be interested in other's thoughts. How to start X windows inside "Bash on Ubuntu on Windows" After installing the new feature (still "Beta") called  that is a feature subset of Windows 10 Anniversary edition, I get the following message when trying to start X-Windows using startx :    What do I need to tweak / configure in order for X-Windows to launch?  I noticed that xauth was already installed, however I had to install the rest of the framework as follows :  apt-get install xorg openbox Editing network interfaces without system rebooting I'd like to make some changes to my networking configuration by editing my /etc/network/interfaces file. What's the cleanest way to make changes to this file and have them take effect, without having to reboot? Typically, I've been doing:   Edit the file service networking restart   But I have the impression that this isn't the "right" way to make these kinds of changes. Arriving at a different port of entry in the same state in USA? I am a girl in my early twenties traveling to USA from India and in my visa application I have provided the contact address for a relative in San Francisco, and their invitation letter. I would like to visit LA first. Will I face problems during immigration if I land in LA (with an immediate on wards ticket to SF)? I dont plan to get on the flight from LA to SFO.  Initially I was planning to fly to SFO from India and then fly to LA immediately after completing immigration at SFO airport. So, after a few sessions, the new player I'd invited has been a bit of a disaster. He doesn't get on well with any of the other players, laughed when someone's character died (in our campaign that's permanent at the moment), and generally has been a nuisance. However, he doesn't seem to notice this. I've talked to him about his behaviour, but it hasn't helped. Several other players have also approached me on their own to register concerns.  The long and short of it is, he's not a good fit for our game or social group, due to his abrasive personality/playstyle (as I and the other players perceive it). He's also not interested in roleplaying (something my group does heavily, at the moment) and continually pushes to place himself in the limelight - which he does by instigating combat and trying to skip over what he sees as 'boring' scenes. His character is a Minotaur barbarian, and the most exotic race in the game, but he only uses it for the stat bonuses, and doesn't even have a backstory - he simply says he doesn't need one. However, I don't want to be rude or otherwise unkind to him, as I will still see him around after he leaves the group, and so will the other players.  How can I politely ask him to leave the group, without being dishonest but avoiding embarrassment for anyone? I also want to avoid seeming to 'abandon' him, or 'go behind his back'.  Note: There are few/no in-game problems with adding or removing characters, and I don't need advice for that. This is strictly about handling the player. The system (not that it's all that relevant to the problem) is I'm reading the proof of the multiplicative property of $$s_k(n)=\sum_{d|(n,k)}f(d)g\bigg( \frac kd\bigg)$$ The book wrote that in order to understand the proof, we need to know if $a,b,k,m$ are integers such that $(a,k)=(b,m)=1$, then $$(ab,km)=(a,m)(b,k).$$  I have written proof, but I don't know is it consistent, and this seems used more tools than it necessarily has to.   My proof: Let $$S_1=\{d: d|(a,m), d&gt;0\}\\S_2=\{d: d|(b,k), d&gt;0\}\\S=\{d:d|(ab,km), d&gt;0\}.$$ I will prove the statement by showing that the function $\phi:S_1\times S_2\to S$ defined as $$\phi(d_1,d_2)=d_1d_2$$ is bijective, and complete the proof by connecting the maximal elements from these partial ordering sets.  Obviously, for $d_1\in S_1, d_2\in S_2$, this tells us $d_1 $ is both divisor of $a$ and $m$, and $d_2$ is both divisor of $b$ and $k$, hence $d_1d_2$ is both divisor of $ab$ and $km$, so we can tell $\phi(S_1\times S_2)\subseteq S$.  To show one-to-one, if we have $c_1,d_1\in S_1$ and $c_2,d_2\in S_2$ such that $$\phi(c_1,c_2)=\phi(d_1,d_2)$$ then $$c_1c_2=d_1d_2$$  In particular, $c_1|d_1d_2$, we need to show $c_1|d_1$. Indeed, if $(c_1,d_2)&gt;1$, this implies $a,k$ have common factor larger than $1$, contradicts the assumption. Therefore $c_1|d_1$. A similar argument implies $d_1|c_1$, therefore $c_1=d_1$. Again a similar argument implies $c_2=d_2$, which shows one-to-one.   To show onto, let $d\in S$, since $d|ab$, we can split $d$ into $d_1d_2$ such that $d_1|a$ and $d_2|b$. Since $(a,k)=1$, we see $(d_1,k)=1$, by property of $S$ we see also $d_1|m$, therefore $d_1\in S_1$, a similar argument implies $d_2\in S_2$. So every number in $S$ has a preimage in $S_1\times S_2$  This completes the proof. Is there any mistake in the proof?     Edit: A proof about the statement: If $d|ab$ then there are $d_1,d_2$ such that $d=d_1d_2$ and $d_1|a, d_2|b$.  Let $ab=p_1^{e_1}\cdots p_r^{e_r}$ for distinct prime factors $p_1,\cdots,p_r$, then we can write $$a=p_1^{x_1}\cdots p_r^{x_r}\\b=p_1^{y_1}\cdots p_r^{y_r}$$ where some of $x_i, y_i$ can be zero, and $x_i+y_i=e_i$ for all $i=1,\cdots,r$.  Since $d|ab$, we can write $$d=p_1^{f_1}\cdots p_r^{f_r}$$ with $f_i\leq e_i$ for all $i=1,\cdots,r$. Then since $$f_i\leq x_i+y_i$$ Split into two cases:   Case 1: $f_i&gt; x_i$, then we can choose $g_i=x_i$ and $h_i=f_i-x_i$.  Case 2: $f_i\leq x_i$, then we can choose $g_i=f_i$ and $h_i=0$.  Then the choice $$d_1=\prod_{i=1}^r p_i^{g_i}, \quad d_2=\prod_{i=1}^r p_i^{h_i}$$ will prove the statement. The question is to show that for any $x,y \in\Re^n$  $||x+y||\cdot||x-y||\le||x||^2+||y||^2$  with equality if and only if $\langle x,y \rangle= 0.$  I have that $||x+y||^2=||x||^2+2 \langle x,y \rangle+||y||^2$ , which helps me prove equality but I'm lost on how to show this and show that the inequality part. Solving the recurrence $T(n) = \sqrt n T(\sqrt{n}) + \sqrt{n}$ A former student of mine was TA-ing an algorithms class last quarter and asked students to solve this famous recurrence relation:  $$T(n) = \sqrt n T(\sqrt{n}) + n$$  There are  and this question has already been asked here.  I was talking to my student about this problem and mentioned that it's quite hard to solve and is pretty dependent on the particular choices being made. As an example, I suggested this variant of a recurrence relation that was less simple to solve:  $$T(n) = \sqrt n T(\sqrt{n}) + \sqrt{n}$$  The TA and I tried solving this recurrence for about an hour and a half without making any progress. Here are a few things we tried:   My approach to solving the initial recurrence relation was to draw out a recursion tree and notice that each level of the tree contributes $n$ to the total and that there are $O(\log \log n)$ layers, so the recurrence solves to $O(n \log \log n)$. When I tried doing this here, I noticed that the work per layer was no longer constant; instead, the top layer sums to $\sqrt{n}$, the second layer to $n^{3/4}$, the third to $n^{7/8}$, etc. We got stuck working with the summation $n^{1/2} + n^{3/4} + n^{7/8} + ...$. We tried using the iteration method to unroll the recurrence. With the original recurrence relation, this works out nicely; here, we got stuck at the same summation given above.   I'm completely stuck trying to figure out how to solve this recurrence relation. There's nothing riding on it per se - I don't need to solve it for any particular reason - but the fact that we arrived at it by a straightforward modification of a common algorithms problem set question makes it all the more enticing.  Any idea how to solve this recurrence?  Thanks! How do I check if a number is a palindrome?  Any language. Any algorithm. (except the algorithm of making the number a string and then reversing the string). Resolve the error "An illegal choice has been detected..." Do I need a visa for a connecting flight to Japan? I'm going to the Philippines this October and would like to layover in Japan. I found a reasonably priced ticket with a 15-hour layover to Haneda, however, I have to transfer to Narita. Do I need a visa since I'm going to have to stay at a hotel and ride a bus to travel to Narita airport? Thank you! 80's Animated movie: An old man joins mission to save a boy stranded on a hostile world A guy on a space ship picks up a distress call, a boy is stranded on a planet with a hostile environment. He &amp; his crew go to the rescue, stopping on the way to pick up an old man who comes with them. Most of the top of the old guy's skull is metal, from an old injury.  They've various adventures on the way (their ship is boarded by pirates/bandits/hostile forces at one point).  They get to the planet with the boy. They've limited time to save him as the planet is being moved back in time. (I can't remember why) When they find the boy, he's being attacked by giant wasp-type-things.   The boy is injured on the top of his head. The old guy dies protecting him. The boy gets shifted back in time with the planet and - you guessed it - survives, grows up and turns out to be the old guy.  Now that I've remembered some of it, the bits I can't remember are driving me crazy. I'd love to see this again, if I could identify it I might be able to track down a copy.  I'd swear I saw this mid 80's on morning TV, but it I could be out by 5 years either way. Thanks How do I copy vertex groups from one object to another? Capital letters in "Theorem", "Conjecture" etc This is my first post and as you can probably guess I am a mathematician so I have no clue about grammar. I am writing a mathematical document at the moment and I would appreciate some advice on my usage of capital letters. Can somebody please confirm if the following are correct?  1) "We know by T​heorem 4.6.1 that..."   2) "the following c​onjecture, due to..."  3) In order to prove the "Mckay-Stevens $k$-covering C​onjecture, once needs to show that..."  I'm particularly confused about 3).  Many thanks for any help Parametric Interpolation of 2D data The relationship of ${\frak m+m=m}$ to AC Is it possible to change the linkage of Nether portals? I have 3 portals that link together, but I want to remove at least the middle one.  Edit for clarification:    The portals I created are 1, 4 and 5, the others were spawned by the game as the "other end". I want to remove the link between 5 and 4 and create a link between 5 and (the yet non-existent) 6.  The goal is to be able to travel to 5 in the route: 1, 2, 6, 5. I don't really need 3 and 4 now. 90s (or early 2000s) scifi (mini)series where a boy and old man chase a black guy in metal suit I'm looking for a 90s (or early 2000s) scifi (mini)series where a boy and old man chase a black guy in metal suit. I think they were going through different dimensions. I remember part of it, but I don't think I ever saw how it ended. I remember my friend telling me there was a twist at the end. I think they were trying to find something and he was always ahead of them.. Hide iPhone HTML5 video play button I want to create an image like below, so a balloon with text on it.     I have been googling for ideas (text, sphere, ....) and came on  earlier question. So I tried Shrinkwrap and Cast modifier.   Here is the situation before applying the modifiers.    This was after trying Shrinkwrap    And this after Cast modifier.    For me it does not look like it is going to work with one of these modifiers.  Question How to create the image of a balloon with text on it ? With one of these modifiers or should I try a complete other approach ?? How to do this ?