Can a glyph of warding be set to activate if a creature of a specific humanoid race touches it? For example, could a glyph of warding be set to activate if a changeling touches it, as a way to detect a disguised changeling?
So, say you are a wizard 15/warlock 2. You have the Lance of Lethargy invocation, which pushes an enemy you target with eldritch blast and hit back 10 feet. Say you put a demiplane entrance ~5 feet behind the enemy you target with it. When you hit, you throw the enemy in. Before all this, you had put a Glyph of Warding in there on one of the surfaces. What would be the limit to the trigger for this? Would it be forced to be touch or proximity, or could you base it off something like hostility towards the caster?      ... When you cast this spell, you inscribe a glyph that later unleashes a magical effect ... You decide what triggers the glyph when you cast the spell. For glyphs inscribed on a surface, the most typical triggers include touching or standing on the glyph, ... (PHB 245)   The key word here is "typical". Based on Google's definition, the informal definition of "typical" is     showing the characteristics expected of or popularly associated with a particular person, situation, or thing.   This means, if my assumption is true, that the triggers in the PHB are only the most common ones. Other than the one about being forcibly at maximum 10 feet in diameter in the PHB, I cannot see a limit. Though I probably should assume this would all be DM discretion, (and I know that I sound like a broken record here) but could the trigger be hostility toward the caster, or something else, like being a specific race, gender, from a specific place, etc., or would it be forced to being something from the PHB?
Proof of an inequality by induction: $(1 + x_1)(1 + x_2)...(1 + x_n) \ge 1 + x_1 + x_2 + ... + x_n$ I am looking for a correct proof of this statement: If $G$ is a group such that $G/Z(G)$ is cyclic, then $G$ is commutative.  Proof: $G/Z(G)$ is isomorphic to $\operatorname{Inn}(G)$ and is cyclic, and then for every $a$ and $b$ in $G$ the inner isomorphisms $\gamma_a$ and $\gamma_b$ satisfy $\gamma_a \gamma_b = \gamma_{ab} = \gamma_{ba} = \gamma_b \gamma_a$, and therefore for every $a,b \in G$, $ab = ba$.  Is that proof complete, or am I missing something? Thanks a lot for the help. If you hash a string using SHA-256 on your computer, and I hash the same string using SHA-256 on my computer, will we generate the same value? Does the algorithm depend on a seed (so we'd both need the same seed) or some other such parameter?  edit:  To clarify, by 'string' I meant 'the same byte input', which as the comments and @ispiro's answer point out, may be different for the same character string depending on the encoding. Closed form solution for slope coefficients in bivariate regression In a univariate regression, $Y=a+bX+e$, the solution for slope b is given by $COV(X,Y)/VAR(X)$.  Is there a similar expression for a bivariate regression $Y=a+bX+cZ+e$. What is the closed form solution for b and c in this case? What's the bad magic number error? What's the "Bad magic number" ImportError in python, and how do I fix it?  The only thing I can find online suggests this is caused by compiling a .py -> .pyc file and then trying to use it with the wrong version of python. In my case, however, the file seems to import fine some times but not others, and I'm not sure why.  The information python's providing in the traceback isn't particularly helpful (which is why I was asking here...), but here it is in case it helps:  Traceback (most recent call last):   File "run.py", line 7, in &lt;module&gt;     from Normalization import Normalizer What is the use of multiple main methods? Is (rest) mass conserved in special relativity? I don't understand why it is said that the (rest) mass of a system is not conserved in relativity. I mean, the momentum of a system is conserved (i.e.: it remains constant in a frame of reference without any external influence). Also the energy of a system is conserved in relativity: it doesn't change without any external agency  and the (rest) mass of a system is just  $$m^2=E^2-p^2$$  $E$ is constant, $p$ is constant, how can $m$ change?  For example, entropy is not conserved in a system, that means that the entropy of the system will increase spontaneously with time, which is really the case. But, is this true for mass?   here is the problem from Griffiths and exact solution as given in the Griffiths,  Two lumps of clay, each of rest mass $m$, collide head-on at $3c/5$ and they stick together. Question: what is the rest mass $M$ of the composite lump?  Solution: In this case conservation of momentum is trivial it is zero before and zero after. The energy of each lump prior to the collision is $$mc^2/\sqrt{1-v^2/c^2} =5mc^2/4.$$ The energy of the composite lump after the collision is $Mc^2$ (since its at rest). so the conservation of energy says: $5mc^2/4 + 5mc^2/4 =Mc^2$ and hence $M=5m/2$.  Notice that this is greater than the sum of the initial masses! Mass was not conserved in this collision; kinetic energy was converted into rest energy, so the rest mass increased. PostgreSQL crash when connection failed Error log is:  016-02-21 21:22:34 GET DETAIL:  Connection matched pg_hba.conf line 83: "host    all             all             ::1/128                 md5" .... .... 2016-02-21 21:22:37 GET DETAIL:  Connection matched pg_hba.conf line 83: "host    all             all             ::1/128                 md5" 2016-02-21 21:22:37 GET FATAL:  password authentication failed for user "postgres" 2016-02-21 21:22:37 GET DETAIL:  Connection matched pg_hba.conf line 83: "host    all             all             ::1/128                 md5" 2016-02-21 21:22:37 GET LOG:  CreateProcess call failed: A blocking operation was interrupted by a call to WSACancelBlockingCall.       (error code 299) 2016-02-21 21:22:37 GET LOG:  could not fork new process for connection: No error 2016-02-21 21:22:37 GET LOG:  incomplete startup packet 2016-02-21 21:22:38 GET FATAL:  password authentication failed for user "postgres" 2016-02-21 21:22:38 GET DETAIL:  Connection matched pg_hba.conf line 83: "host    all             all             ::1/128                 md5" 2016-02-21 21:22:42 GET FATAL:  password authentication failed for user "postgres" 2016-02-21 21:22:42 GET DETAIL:  Connection matched pg_hba.conf line 83: "host    all             all             ::1/128                 md5" 2016-02-21 21:24:26 GET LOG:  could not receive data from client: An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full. 2016-02-21 21:24:26 GET LOG:  incomplete startup packet 2016-02-21 21:24:29 GET FATAL:  password authentication failed for user "postgres" 2016-02-21 21:24:45 GET PANIC:  could not write to log file 000000010000000100000041 at offset 4259840, length 8192: Invalid argument 2016-02-21 21:24:45 GET STATEMENT:  COMMIT 2016-02-21 21:24:53 GET LOG:  server process (PID 470944) was terminated by exception 0xC0000409 2016-02-21 21:24:53 GET DETAIL:  Failed process was running: COMMIT 2016-02-21 21:24:53 GET HINT:  See C include file "ntstatus.h" for a description of the hexadecimal value. 2016-02-21 21:24:53 GET LOG:  terminating any other active server processes   Can anyone help to solve the problem? I spent many hours but didn't find a solution.   Postgres version 9.4 Operating System: Windows  postgresql.conf is:  listen_addresses = '*' port = 5432  max_connections = 100 shared_buffers = 128MB   dynamic_shared_memory_type = windows   pg_hba.conf is:  # IPv4 local connections: host    all             all             127.0.0.1/32            md5 host    all             all             0.0.0.0/0               md5 Why does TeX prefer an overfull box to hyphenating here? I'm trying to understand at a deeper level the ubiquity of log-likelihood (and perhaps more generally log-probability) in statistics and probability theory.  Log-probabilities show up all over the place: we usually work with the log-likelihood for analysis (e.g. for maximization), the Fisher information is defined in terms of the second derivative of the log-likelihood, entropy is an expected log-probability, Kullback-Liebler divergence involves log-probabilities, the expected diviance is an expected log-likelihood, etc.    Now I appreciate the many practical and convenient reasons.  Many common and useful pdfs are from exponential families, which leads to elegantly simplified terms when log-transformed.  Sums are easier to work with than products (esp for differentiating).  Log-probs have a great floating point advantage over straight probs.  Log-transforming a pdf often converts a non-concave function into a concave function.  But what is the theoretical reason/justification/motivation for log-probs?  As an example of my perplexity, consider the Fisher information (FI).  The usual explanation for intuiting the FI is that the second derivative of the log-likelihood tells us how "peaked" the log-likehood is:  a highly peaked log-likelihood means the MLE is well-specified and we are relatively sure of its value, while a nearly flat log-likehood (low curvature) means many different parameter values are nearly as good (in terms of the log-likelihood) as the MLE, so our MLE is more uncertain.   This is all well-and-good, but isn't it more natural to just find the curvature of the likelihood function itself (NOT log-transformed)?  At first glance the emphasis on the log-transform seems arbitrary and wrong.  Surely we are more interested in the curvature of the actual likelihood function.  What was Fisher's motivation for working with the score function and the Hessian of the log-likelihood instead?  Is the answer simply that, in the end, we have nice results from the log-likelihood asymptotically? E.g., Cramer-Rao and normality of the MLE/posterior.  Or is there a deeper reason? How to safely remove proprietary Intel driver I recently installed the proprietary Intel drivers for my Toshiba Satellite A105 s4284 running Ubuntu 14.10. Nouveau was working just fine, I was just attempting to make it so that I was able to run CS:S (no need for explanation on that.)  Long story short, I went and downloaded the Intel Graphic Drivers for Linux* from . After downloading and installing the .deb, I ran intel-linux-graphics-installer which opened up a window that downloaded &amp; installed the open Intel drivers. I then rebooted, and it's slow. Very slow, especially on 3D effects and when I hit Alt+Tab.  Now, I don't know if the previously installed Nouveau drivers are conflicting with these new Intel drivers (if that's the issue, what should I do about fixing it?) What I do know is that my system isn't behaving right and I want it to (obviously.) If removing the Nouveau drivers isn't the solution, how can I safely remove the just-installed Intel drivers?  Does anyone have any suggestions? real memory usage How does gravity work on Star Wars ships? Inspired by the question , how does gravity work on the Millennium Falcon and other ships its size? The passengers are not strapped in and regularly move around just easily as they would on a planet with Earth's gravity.   The answer for the Death Star refers to gravity often being "coreward" (presumably taking advantage of the natural gravity an object of such substantial mass would have), but that doesn't apply for a small ship. So how is gravity accomplished? Why did the Tethered form a line in Us? In Jordan Peele's  we see that the Tethered plan a revolt, rise above ground and start murdering everyone in sight and then they form a line by holding hand in hand.   What was the purpose of that? Alternate property name while deserializing What would be a good term for continuous testing post-deployment? I'm thinking of live production sites here, where there is a continuous community or much content being updated, sort of like a newspaper site or community site (the one I work at is a healthcare improvement company) and we have news articles, programs and so on.  While the underlying code is tested and released there are often production issues that come up, maybe certain pages stop working, style sheets suddenly don't appear like they did due to a service patch or some tweak done to improve production security or performance.  There is Acceptance Testing for when a deployment goes out to make sure things work right, Regression Testing to make sure nothing has been broken since previous releases.  Considering we've done these types of tests and things are working fine what would you call testing, or checking, the site to make sure things still work fine?  To be sure new pages are being crawled for search indexing?  To check that newly added pages are using plug-ins correctly?  Or so on.  My manager and I were discussing some issues that have cropped up and decided we needed to do something like this, but then to sort of note it in our status reports we didn't really have a name for it.  Anyone done this and have a term that might be good?  Or would you consider it covered by something like Continuous Acceptance Testing or some such term? How to to calculate the hash of an unordered set Suppose I have a set of elements, with known hash (e.g. SHA-2). How can I calculate the hash of the set? With it I mean an unordered set, so the order of elements is undefined and shall not play any role in determining the hash of the set.  In theory any commutative operation applied to the hashes should be fine, but I have the strong feeling that XORing all of them together is quite unsafe. An attacker could add an element to the set to produce a hash collision, although finding an element with that wanted hash is as hard as breaking the hash of the whole set.  Anything better solution than the trivial one of sorting the elements into a list, calculating their hashes and then calculating the hash of the hash list?  I think Merkle trees can't help here if they are based on some sort of ordering of the elements. What causes the texture of bread to be open, ie with lots of large holes, or close, ie a regular, uniform tender crumb with no large holes? How can I achieve either? Is there a way to write binary literals in C#, like prefixing hexadecimal with 0x? 0b doesn't work.  If not, what is an easy way to do it? Some kind of string conversion? Unable to install Cisco Packet Tracer 7.3 on Ubuntu 20.04 I am trying to install Packet Tracer 7.3 (latest version) on Ubuntu 20.04 but do not succeed to so so because of two dependencies which are not installable ("libdouble-conversion1" and "qt-at-spi").  However I successfully installed the previous version (7.2.2) which was available in an Ubuntu installer format (.run file) but I nothing happens when I run it from my gnome desktop.  I am quite a newbie in Linux so I appologies if answers are obvious...  Thanks in advance ;-)  Denis