I'm using this formula in my main worksheet in cell N3:   =IFERROR(INDEX(Totals!M$3:M$33,MATCH($B3,Totals!$K$3:$K$33,0)),0)   Details:   $B3 lists first/last names on main worksheet. Totals!$K$3:$K$33 lists first/last names on "Totals" worksheet. M$3:M$33 contains a numbers.   I'm looking for a way to count the numbers in column "M" if the names in column "K" match/are duplicates.  Row 3     "K" = David / M = 39  Row 4     "K" = Angela / M = 53  Row 5     "K" = Angela / M = 3  Row 6     "K" = Paul / M = 61  Row 7     "K" = Betty / M = 49  Desired result: If $B3 = Angela, then "56" is the result found in cell N3 on the main worksheet.
I have a simple spreadsheet, two columns "Amount" (col Q) and "Account" (col O).  I want to get the sum of the "Amount" column where the corresponding "Account" forum equals "Paypal".  This is as far as I can get!  =SUM(Q:Q)*(O:O="Paypal")
Is there any uncountably infinite set that does not generate the reals? Does there exist an uncountably infinite set $X \subseteq \mathbb R$ such that $\mathbb R \neq \left&lt;X\right&gt;$? I can't think of any, but I'm also having trouble trying to prove that no such subset exists.  For example: $\mathbb R$ is uncountable and obviously $\mathbb R = \left&lt;\mathbb R\right&gt;$. The Cantor set $C$ is uncountable, and we know that $C - C = [0, 1]$, so then since $\mathbb R = \left&lt;[0, 1]\right&gt;$ we know that $C$ also generates $\mathbb R$. Also the set of irrationals $\mathbb R \setminus \mathbb Q$ is uncountable, but we can generate all the rational numbers by fixing one irrational number $\alpha$ and then saying the any rational number $x$ shall be $(\alpha + x) - \alpha$, since both $\alpha + x$ and $\alpha$ are irrational.  So the examples that quickly come to mind all generate the reals. Is there a simple counterexample? Why is an orthogonal matrix called orthogonal? C++ virtual function from constructor Why the following example prints "0" and what must change for it to print "1" as I expected ?  #include &lt;iostream&gt; struct base {    virtual const int value() const {       return 0;    }    base() {       std::cout &lt;&lt; value() &lt;&lt; std::endl;    }    virtual ~base() {} };  struct derived : public base {    virtual const int value() const {       return 1;    } };  int main(void) {    derived example; } Imagine a situation in which the whole place is on fire, a bomb is about to explode, everyone is running for their lives and someone is checking his looks on the mirror... pretty inappropriate for the situation, don't you think? I'm looking for an idiom or colloquial/slang/informal expression to describe such an indifferent stance. How do I set a monitor resolution that is not available in the Display Settings dialog? Meaning of the chemical potential for a boson gas My lecturer told me that $\mu$, the , is zero or negative, and in the following example, mathematically it acts as a normalization constant. But is there any physical insight about why boson gas can be zero or negative? I think it is due to the fact the photon gas can pop up from nowhere (i.e. vacuum fluctuation). $$ f_{BE}(\varepsilon)=\dfrac{1}{e^{(\varepsilon-\mu)/(k_B T)}-1}$$ Quoted headings are rendered properly on preview but not when posted With markdown, you can use some dashes for headings. For example, this: Hello ---- this is some other text  renders as this: Hello this is some other text This is fine and works well. When I want to quote that text is when the problem arises, since this Markdown: &gt; Hello &gt; ---- &gt; this is some other text  When written down shows well in the preview but not when posted:  Hello this is some other text   As an example, see an screenshot of the preview:    and a screenshot of the posted content, where the ---- becomes a &lt;hr&gt;:  Note a similar bug I also reported: . Bash script doesn't see SIGHUP? I've got the following script:  #!/bin/bash echo "We are $$" trap "echo HUP" SIGHUP cat    # wait indefinitely   When I send SIGHUP (using kill -HUP pid), nothing happens.  If I change the script slightly:  #!/bin/bash echo "We are $$" trap "kill -- -$BASHPID" EXIT    # add this trap "echo HUP" SIGHUP cat    # wait indefinitely   ...then the script does the echo HUP thing right as it exits (when I press Ctrl+C):  roger@roger-pc:~ $ ./hupper.sh  We are 6233 ^CHUP   What's going on? How should I send a signal (it doesn't necessarily have to be SIGHUP) to this script? points out that certain key and block lengths were a requirement for the AES submissions:     The candidate algorithm shall be capable of supporting key-block combinations with sizes of 128-128, 192-128, and 256-128 bits.   My question is this; how can having a key length that is greater than the block size enhance security?  If we look at ECB mode for simplicity, when the key length is equal to the block length we have a permutation relationship between the set of all plaintexts and the set of all ciphertexts.  Once you increase the key length beyond that, you start to introduce collisions. In fact, you only introduce collisions from then on don't you? Collisions in the sense that a key will create the same ciphertext-plantext relationship as another key.  This would lead me to believe that only part of the key-space is unique, and only that part of key-space needs to be brute-forced?  I know that I am clearly incorrect, I just don't understand why. Automatic vacuum fails with `ERROR: XX000: cache lookup failed for type 0` I've been noticing something like this popping up every 15 seconds in my server logs:  2020-01-30 21:10:30 UTC::@:[24969]:ERROR: XX000: cache lookup failed for type 0 2020-01-30 21:10:30 UTC::@:[24969]:CONTEXT: automatic vacuum of table "myschema.mytable" 2020-01-30 21:10:30 UTC::@:[24969]:LOCATION: get_typlenbyval, lsyscache.c:2036   When I manually run a VACUUM ANALYZE myschema.mytable; it runs without any error, and the error in my logs goes away. However, inevitably, it returns again at some point.   The table in question is defined as follows:  tfs_dev=&gt; \d myschema.mytable;                                                    Table "myschema.mytable"    Column    |   Type    | Collation | Nullable |                                  Default -------------+-----------+-----------+----------+---------------------------------------------------------------------------  level       | text      |           | not null |  id          | integer   |           | not null | nextval('myschema.mytable_id_seq'::regclass)  text_id     | text      |           |          |  name        | text      |           |          |  geom        | geometry  |           |          |  valid_dates | tstzrange |           |          | tstzrange(NULL::timestamp with time zone, NULL::timestamp with time zone)  adjacent    | integer[] |           |          |  valence     | integer   |           |          |  color       | smallint  |           |          | 0 Indexes:     "mytable_pkey" PRIMARY KEY, btree (level, id)     "mytable_text_id_key" UNIQUE CONSTRAINT, btree (text_id)     "mytable_gix" gist (level, geom, id, text_id, name)     "mytable_spgix" spgist (geom)     "mytable_text_id_ix" btree (text_id, level, id, name) Referenced by:     TABLE "otherschema.othertable" CONSTRAINT "othertable_mytable_fk" FOREIGN KEY (level, level_id) REFERENCES myschema.mytable(level, id)     TABLE "otherschema.othertable2" CONSTRAINT "othertable2_mytable_fk" FOREIGN KEY (level, level_id) REFERENCES myschema.mytable(level, id)   Many other posts with a similar error seem to be about a foreign data wrapper, which is present in this database, but not with this table/schema. This is the gift that my dad sent (to) me This is the gift that my dad sent me on my birthday.   Vs   This is the gift that my dad sent to me on my birthday.  Is to required?   Also   Presenting you guys, the trailer of the film.   Vs   Presenting to you guys, the trailer of the film.    Is to required? Environment for two columns with lstlistings In order to reduce copy-pasting, I want to create an environment that will produce a two-column table with headers and two listings in different languages, like below:  \begin{tabular}{l l} Python &amp; Haskell \\ \hline \\ \lstset{language=Python} \begin{lstlisting} A \end{lstlisting} &amp; \lstset{language=Haskell} \begin{lstlisting} B \end{lstlisting} \end{tabular}   I want to use it like below, hiding everything but code:  \begin{comparison} A \vs B \end{comparison}   So far I tried making two new environments (instead of a \vs command inside) with \lstnewenvironment, where first environment had \tabularx command and second \endtabularx. I also tried creating normal \newenvironment for this tabular, &amp; for \vs command and manually inserting \begin{lstlistings} and \end{lstlistings} with code, but it stopped compiling when I put lstlistings inside.  How can I create such an environment?  EDIT: The most compact version I've came up with until now is  \newenvironment{comparison} {\begin{parcolumns}[nofirstindent,distance=0pt,colwidths={1=0.35\textwidth}]{2}} {\end{parcolumns}}  \lstnewenvironment{python} {Python \lstset{language=Python,frame=t}} {}  \lstnewenvironment{haskell} {Haskell \lstset{language=Haskell,frame=t}} {}   which is used like that:  \begin{comparison} \colchunk{ \begin{python} A \end{python} } \colchunk{ \begin{haskell} B \end{haskell} } \end{comparison}   I'm still unable to hide \colchunk{} within python or haskell environments. Appending the same string to a list of strings in Python Your content must have a ListView whose id attribute is 'android.R.id.list' What is a valid use case for an "execute only" file permission? I was reading up on chmod and its .  I saw that 1 is execute only.  What is a valid use case for an execute only permission?  To execute a file, one typically would want read and execute permission.  $ echo 'echo foo' &gt; say_foo $ chmod 100 ./say_foo $ ./say_foo bash: ./say_foo: Permission denied $ chmod 500 ./say_foo $ ./say_foo foo What is the structure in "as best you can"? I instinctively translate it "as best as you can", however this makes no sense.  What is the real structure behind this phrase?  I'll include an  to illustrate the historical presence of this phrase:    Whatever the structure is, I'm guessing that it has something to do with 19th century grammar. Is the cofinite topology on an uncountable set first countable? Let $X$ be any uncountable set with the cofinite topology. Is this space first countable?  I don't think so because it seems that there must be an uncountable number of neighborhoods for each $ x \in X$. But I am not sure if this is true. Are there gotchas using varargs with reference parameters I have this piece of code (summarized)...  AnsiString working(AnsiString format,...) {     va_list argptr;     AnsiString buff;      va_start(argptr, format);     buff.vprintf(format.c_str(), argptr);      va_end(argptr);     return buff; }   And, on the basis that pass by reference is preferred where possible, I changed it thusly.  AnsiString broken(const AnsiString &amp;format,...) { ... the rest, totally identical ... }   My calling code is like this:-  AnsiString s1, s2;     s1 = working("Hello %s", "World");     s2 = broken("Hello %s", "World");   But, s1 contains "Hello World", while s2 has "Hello (null)". I think this is due to the way va_start works, but I'm not exactly sure what's going on. I don't understand the proof to the a/m claim. How we know that $\eta &lt; \kappa$ and $(\alpha,\beta)&lt;_{cw} (0, \eta) $ and hence $h: \mu \to \eta \times \eta$ is injective? Appreciate if anyone could advise.  Here is an excerpt of the proof:  For an infinite ordinal $\kappa,$ the canonical well-ordering of $\kappa \times \kappa,$ denoted by $&lt;_{cw}$ is defined as follows: $(\alpha_1, \beta_1)&lt;_{cw} &lt; (\alpha_2, \beta_2)$ iff either one of the following holds.  $(1): \max\{\alpha_1,\beta_1\} &lt; \max\{\alpha_2,\beta_2\}$  $(2): \max\{\alpha_1,\beta_1\} =\max\{\alpha_2,\beta_2\}$ and $\alpha_1&lt;\alpha_2$   $(3): \max\{\alpha_1,\beta_1\} =\max\{\alpha_2,\beta_2\}$ and $\alpha_1 = \alpha_2$ and $\beta_1 &lt; \beta_2.$  Claim: For all infinite cardinals $\kappa, (\kappa \times \kappa, &lt;_{cw}) \cong (\kappa, \in).$  Proof: (It has been show that it is true for $\kappa = \omega$) Assume there is a counterexample  $\kappa.$ Let $A= \{\lambda \in \kappa + 1| \lambda\geq \omega \ is \ a \ cardinal \ and \ (\lambda \times \lambda, &lt;_{cw}) \not\cong (\lambda, \in)\}.$ Then, $\kappa \in A.$ Let $\mu$ be least element of $A.$ Thus, $\mu &gt; \omega$ and for all $\lambda,$ if $\omega \leq \lambda &lt; \mu$ and $\lambda$ is a cardinal, then $(\lambda \times \lambda, &lt;_{cw}) \cong (\lambda, \in).$  By Comparability theorem, $(\mu, \in)$ is isomorphic to initial segment of $(\mu \times \mu, &lt;_{cw})$ since $|\mu \times \mu| \geq \mu$ and $\mu$ is cardinal. Let $(\alpha, \beta) \in \mu \times \mu$ such that $(\mu, \in)$ is isomorphic to initial segment of $(\mu \times \mu, &lt;_{cw})$ given by $(\alpha, \beta).$ Let $h$ be the isomorphism. Let $\eta= \max\{\alpha, \beta\}+ \omega.$ Then $\eta &lt; \kappa$ and $(\alpha,\beta)&lt;_{cw} (0, \eta).$ HENCE, $h: \mu \to \eta \times \eta$ is injective. date difference in days, in Android