I learned that "had", or past perfect is usually used with a dead entity. But what if I am not trying to emphasize the fact that an action had taken place before that entity died? Such as:     My dead grandfather has stepped on a mine (when he was alive).   This sentence is resultative, showing why he died, and uses present perfect.  And this sentence below:     My dead grandfather stepped on a mine (on July 6, 1995).   This sentence is incorporating the specific date at which he stepped on a mine, therefore using simple past tense.  Are the uses of simple past and present perfect tense above valid?
I remember (vaguely) reading somewhere that it is wrong to use the present perfect when the subject of a sentence is someone who is long dead:     *Einstein has visited the Philippines.   My question is, What if the dead person is not the subject but an object:     Leo is the best president our country has/had ever had. (The ones who   succeeded him were inferior, even our current president.)   Which tense is proper here
Trigonometric Uncertainty Propagation This question is prompted by:  and .  Basically, some diamond moderators don't always want to diamond-hammer close questions.  A workaround is to create a new account, , then cast regular close votes from that account.  Question: May a diamond moderator utilize a second, non-diamond account e.g. to cast regular close votes?     It is not a problem to have multiple accounts, as long as they aren't voting for each other and doing other sockpuppet-y things.      I worry this might be considered "sockpuppet-y".  The diamond close hammer is sometimes excessive, particularly  where moderators are . sed : Ignore line starting whitespace for match I want to replace the default listening port of httpd to 9090. I can edit the line in httpd.conf file using below  sed -i "/^Listen/c\Listen 9090" /etc/httpd/conf/httpd.conf   But the line   Listen 80   may have white space before it.  How do I ignore this white space to match this line? Why is polyploidy lethal for some organisms while for others is not? is the multiplication of number of chromosomal sets from 2n to 3n (triploidy), 4n (tetraploidy) and so on. It is quite common in plants, for example many crops like wheat or Brassica forms. It seems to be rarer in animals but still it is present among some amphibian species like Xenopus.  As I know in mammals polyploidy is lethal (I don't mean tissue - limited polyploidy). I understand that triploidy is harmful due to stronger influence of maternal or paternal epigenetic traits that cause abnormal development of placenta, but why there is no tetraploid mammals? How to grep for text in a file and display the paragraph that has the text? Execution of a command locally after ssh tunneling I have a script file ./run_app.sh which contains of the following:  ssh -L 8888:localhost:8888 ubuntu@address ./run_website.sh   # it should be executed locally   but it tries to run the second line on the remote machine. Actually, I want to run it on my pc. Any idea? How should we deal with duplicate answers? How to change this matrix with respect to standard basis? Given the basis $\beta = \{ (1, 1, 0),\ (1, 0, -1),\ (2, 1, 0)\}$ and the matrix:  $$ A =         \begin{bmatrix}         1 &amp; 1 &amp; 0 \\         1 &amp; 1 &amp; 0 \\         0 &amp; 0 &amp; 1 \\         \end{bmatrix} $$  with respect to  $\beta$.  How to change this matrix with respect to standard basis? $\Bbb Z^\ast$ What is this notation? What does $\Bbb Z^\ast$ mean? I would think some subset of the integers but I cannot find a definition. Thank you. Is it time for Stack Exchange, Inc and the community to legally separate amicably? There's no need to  the  that have led to a lack of trust between  of  and . Suffice it to say that astoundingly they continue to assert that  and, instead of apologizing and reinstating Monica have demanded that she go through a process with no transparency, due process, or involvement from the community.   Has the time has come for Stack Exchange, Inc to spin off the community and all the data needed to keep the sites running to a separate non-profit, who would then in turn license the software from the company?  What's in it for the community?   The community can practice self determination for issues from as basic as the number of moderators they have to as fundamental as the policies they enforce. If the company development continues to be unresponsive to the community's needs, the community would be able to develop its own open source software that would meet its needs. They can find their own funding model instead of having ads imposed on them.   What's in it for the company?   Community actions will no longer reflect on the company. Interaction with the community as a customer may come more naturally to current leadership than the present paradigm. They don't have to worry about paying for the community's operating expenses. They can focus on doing one thing well. This is the code that's giving me trouble.   f = Frame(root, width=1000, bg="blue") f.pack(fill=X, expand=True)  l = Label(f, text="hi", width=10, bg="red", fg="white") l.pack()   If I comment out the lines with the Label, the Frame displays with the right width.  However, adding the Label seems to shrink the Frame down to the Label's size.  Is there a way to prevent that from happening? Commandline shortcut for current directory similar to ~ for home directory? Equivalence Relation problem Let $S$ be the relation on $\mathbb{N} \times \mathbb{N}$ defined by $(a,b)S(c,d)$ if and only if $ad=bc$. Prove this is an equivalence relation on $\mathbb{N} \times \mathbb{N}$.  I think I've found this to be reflexive and symmetric, but I'm stuck on transitivity. Can someone check my work so far and assist with testing transitivity?  Reflexive: Let $(x,y)S(x,y)$. Then $xy = yx$. So $S$ is reflexive. Symmetric: Suppose $(a,b)S(c,d)$. Then, $ad = bc$. Therefore, $da = cb$ and $cb = da$. Therefore, $(c,d)S(a,b)$. Thus, $S$ is symmetric.  Transitive: Suppose $(a,b)S(b,c)$. Then $ac = bb$.   This is where I'm stuck. Any ideas? I need to calculate no of possible substrings containing "00" as a substring. I know the length of the binary string.  Eg: for a string of length 4, possible substrings are: 0000 0001 0010 0011 0100 1000 1001 1100  I just need the number of possible combinations, not enumerate all of them. I have an HP laptop with with a Core-i5 450m processor and an ATI Radeon 5650 1GB graphics card. When I played crysis warhead on my system its temprature went up to 82° c. Is it safe to play games up to this temperature level? I checked this  but didn't fully understand it.   I know that the volume of a right circular cone is $V = \frac{1}{3}\pi x^2h$  I know that I must take the first derivative and set it equal to zero, which will find the maximum.   My problem is how to deal with the variable $h$, the height?   How can I rewrite that in terms of $x$ or $r$.      I have tried to implicitly differentiate this equation, but that wasn't helpful for me. What is the "Install this third-party software" box in the installer and what third-party software is installed? How do I boot my PC from GRUB? Is it correct to use the word "birthday" for the deceased, or is there a better alternative? How does one refer to the birthdate of someone who is no more, we usually say  Today is my uncle's 80th birth anniversary (Common in Indian English, not sure if it's correct)  or  Today would have been my uncle's 80th birthday   Is it right to say  "Today is my uncle's 80th birthday" for an uncle who is dead? Declare a global variable in a Blender session