Can not install jdownloader in 18.04
"Unable to locate package" while trying to install packages with APT
It can be proved that there are two irrational numbers $a$ and $b$ such that $a^b$ is rational (see ) and that for each irrational number $c$ there exists another irrational number $d$ such that $c^d$ is rational (see ).  My question is: Is there an irrational number $a$ such that $a^a$ is rational (and how could you prove that)? TeXShop and Mac preview crashing when opening latex/beamer built pdfs After updating to Sierra 10.12.4 last week, TeXShop crashes:   when opening an existing .tex document that has a pdf associated to it immediately after compiling a new document, i.e. as soon as a pdf is created.   Furthermore, preview crashes opening almost any pdf that has been created with TeXShop. There is virtually nothing on the internet about it, and the only solution seems to be a complete reinstall of MacOSX (so as to reinstall the supposedly broken preview), which I'd like to avoid if at all possible.  Someone else has described a similar issue, but has not received any responses ().  I would be very grateful for some help, as I can neither produce work, nor look at any at the moment. Many thanks! I had a problem with the laptop lid so I am using it with an external monitor. I was wondering if there is any way to power on the laptop without opening the lid, that is through ports.  Laptop: Dell Inspiron 1525 I noticed that Dolores Umbridge was born during the first Wizarding War, so it's very likely she wasn't a Death Eater then (but she is pretty evil -- who knows?).  After that Voldemort was not around in a way that could affect many people, and most wouldn't know he was planning to rise again.  During that time, and up through Voldemort's return (in Goblet of Fire), did Umbridge have any connection with the Death Eaters or with Voldemort?  Was she doing what she did on her own, or was it because of an association with Voldemort or his allies? The script I use is actually returning this output:  (source /Thetra/Commun/env_ora.sh &gt;/dev/null; sh aclenv/arun)  geIlgif0t1 -DVORACLE geIlgif0t1 prg_25900: ACOMP=X geAhadlAd1 -DVORACLE geAhadlAd1 prg_25948: ACOMP=A syCcgge0t1 -DVORACLE syCcgge0t1 prg_26023: ACOMP=S2 syVcalq0t1 -DVORACLE syVcalq0t1 prg_26071: ACOMP=Y syVvali0t1 -DVORACLE syVvali0t1 prg_26119: ACOMP=Y syAedit0t1 -DVORACLE syAedit0t1 prg_26167: (1312) DBMS WARNING: Column not found in table. (-11238)   RETURN (-6)     END  END     END     IF cm_para_f2('VDEF','abQtip_0n1','unicite',syAedit0t1:$v_unicite)&lt;&gt;0      OR null_convert$(syAedit0t1:$v_unicite,'R') &lt;&gt; 'F' THEN SET syAedit0t1:$v_unicite TO 'R'     SET $v_tips_mrgl TO 'S'     SET $v_rfbt_iban, $v_rfbt_intitule, $v_orga_creancier, $v_orga_tip_adr1, $v_orga_tip_adr2,         $v_orga_tip_adr3, $v_code_docu, $v_tips_centre, $v_code_etab, $v_orga_tip_emetteur,  $v_orga_emetteur, $v_rfbt_compte, $v_orga_banque, $v_rfbt_emetteur TO     SELECT rfbt_iban, rfbt_intitule, orga_creancier, orga_tip_adr1, orga_tip_adr2, orga_tip_adr3 ACOMP=N syAvali0t1 -DVORACLE syAvali0t1 prg_26215: (2751) DBMS WARNING: Column not found in table. (-11238)  + to_string_using$(str_to_val$(substr$(clip_str$(to_string$($f_imme_no)),1,4)),'&amp;&amp;&amp;&amp;')         + to_string_using$(str_to_val$(substr$(clip_str$(to_string$($f_sepa_propriete_no)),1,5)),'&amp;&amp;&amp;&amp;&amp;')     IF syAvali0t1:$v_unicite ='R' THEN  SET $v_sepa_rum3 TO $v_sepa_rum3 + substr$(to_string_using$(syAvali0t1:$v_ordr_direct,'&amp;&amp;&amp;&amp;&amp;&amp;&amp;&amp;&amp;'),7,9)     ELSE ACOMP=N syAcalc0t1 -DVORACLE syAcalc0t1 prg_26263: ACOMP=N syAcalc0t2 -DVORACLE syAcalc0t2 prg_26311: ACOMP=N syAcalc0t3 -DVORACLE syAcalc0t3 prg_26359: ACOMP=N   To check for errors I use the following command:  (source env_ora.sh &gt;/dev/null; sh aclenv/arun) | egrep '^ACOMP=$'   Output:  (1312) DBMS WARNING: Column not found in table. (-11238)   RETURN (-6)     END  END     END     IF cm_para_f2('VDEF','abQtip_0n1','unicite',syAedit0t1:$v_unicite)&lt;&gt;0      OR null_convert$(syAedit0t1:$v_unicite,'R') &lt;&gt; 'F' THEN SET syAedit0t1:$v_unicite TO 'R'     SET $v_tips_mrgl TO 'S'     SET $v_rfbt_iban, $v_rfbt_intitule, $v_orga_creancier, $v_orga_tip_adr1, $v_orga_tip_adr2,         $v_orga_tip_adr3, $v_code_docu, $v_tips_centre, $v_code_etab, $v_orga_tip_emetteur,  $v_orga_emetteur, $v_rfbt_compte, $v_orga_banque, $v_rfbt_emetteur TO     SELECT rfbt_iban, rfbt_intitule, orga_creancier, orga_tip_adr1, orga_tip_adr2, orga_tip_adr3 (2751) DBMS WARNING: Column not found in table. (-11238)  + to_string_using$(str_to_val$(substr$(clip_str$(to_string$($f_imme_no)),1,4)),'&amp;&amp;&amp;&amp;')         + to_string_using$(str_to_val$(substr$(clip_str$(to_string$($f_sepa_propriete_no)),1,5)),'&amp;&amp;&amp;&amp;&amp;')     IF syAvali0t1:$v_unicite ='R' THEN  SET $v_sepa_rum3 TO $v_sepa_rum3 + substr$(to_string_using$(syAvali0t1:$v_ordr_direct,'&amp;&amp;&amp;&amp;&amp;&amp;&amp;&amp;&amp;'),7,9)     ELSE   We can see that grep is returning non matching lines.  When I redirect the stderr to stdout with this command:  (source /Thetra/Commun/env_ora.sh &gt;/dev/null; sh /Thetra/Oracle/transfert/P2016.H.1/aclenv/arun) 2&gt;&amp;1 | egrep '^ACOMP=$'   As expected, the output is void.  Why grep is returning non matching lines when stderr is not redirected ? I found this pretty good small research, but I am still concerned about "regular usage" in life, say, when I am talking in the office, especially because of this comment:     To me: Stone is something you can pick up with one hand (for   throwing). A rock takes two hands. Cheaper alternative to parmesan cheese? The parmesan cheese in pasta recipe is quite expensive.....do we have cheaper alternative??  Are there are cheddar cheese which can replace parmesan cheese? Suppose $x&gt;0$ and we have function $f(x)=\frac{\sin x}{x}$ how can we show $$\forall n \in \mathbb{N} :|f^{(n)}(x)|\leq \frac{1}{n+1}$$ I need a hint to show this property .Thanks in advance . I tried for $n=1 ,2$  by finding maximum of $|f'| ,|f''|$ but I get stuck to show for $n$ Why is Dictionary preferred over Hashtable in C#? In most programming languages, dictionaries are preferred over hashtables. What are the reasons behind that? Print file content without the first and last lines $X$ and $Y$ i.i.d., $X+Y$ and $X-Y$ independent, $\mathbb{E}(X)=0 $ and $\mathbb{E}(X^2)=1$. Show $X \sim N(0,1)$ $X$ and $Y$ are independent and identically distribued (i.i.d.), $X+Y$ and $X-Y$ are independent, $\mathbb{E}(X)=0$ and $\mathbb{E}(X^2)=1$. Show that $X\sim N(0,1)$.  We should use characteristic functions to prove this. Any ideas? Our iPad is locked and we're not sure of the Apple ID / iCloud password I am reading Velleman's "How to Prove it", and in one example he proves  $\neg \exists x P(x)  \implies \forall x \neg P(x)$    in the following way:    Suppose $\neg \exists x P(x)$. Let x be arbitrary. Suppose $P(x)$. Since we have a specific $x$ for which P(x) is true, it follows that $\exists x P(x)$, which is a contradiction. Therefore $\neg P(x)$. Since $x$ was arbitrary, we can conclude that $\forall x \neg P(x)$, so $\neg \exists x P(x)  \implies \forall x \neg P(x)$    What makes me confused is the line in bold text, that is "Suppose $P(x)$". The reason is that he writes that he is doing proof by contradiction, but $P(x) \not\iff \neg\forall x \neg P(x)$. He is not treating all possible cases where $\forall x \neg P(x)$ is false by assuming $P(x)$, does he? So how can this be a valid proof by contradiction?    Edit: I deleted my first example since it was clearly not representative for the problem.  Edit 2: So the thing that I am opposing I guess is that $\neg \forall x \neg P(x)$ is not $P(x)$. And from what I have undestood, a proof by contradiction should use the negation of the consequent which I do not think that Velleman does. Cutting a circular hole in a hollow cylinder without distorting the cylinder Whenever I try to cut out a circular hole in either a cylinder or sphere the polygons around the circular hole always have distorted normals after smoothing. Is there anyway to fix this. I've tried using the remesh modifier but wind up with some pretty ugly results. In Shakespeare's Macbeth, the Third Witch says to Banquo: "Thou shalt get kings, though thou be none" (1.3.65); if I want to quote that line and write it in the third person singular, how should I conjugate the verbs "shall" and "be" correctly? How many Shutter Clicks on a New Camera considered normal?    I purchased a quotes new Nikon D750 and checked the shutter count and it has 264 Shutter Clik count on it.    Is that suspect of a returned purchase or used camera? How can I convert a string to boolean in JavaScript? Can I convert a string representing a boolean value (e.g., 'true', 'false') into a intrinsic type in JavaScript?  I have a hidden form in HTML that is updated based upon a user's selection within a list. This form contains some fields which represent boolean values and are dynamically populated with an intrinsic boolean value. However, once this value is placed into the hidden input field it becomes a string.  The only way I could find to determine the field's boolean value, once it was converted into a string, was to depend upon the literal value of its string representation.  var myValue = document.myForm.IS_TRUE.value; var isTrueSet = myValue == 'true';   Is there a better way to accomplish this? Reopened questions get a "modified" time stamp in the questions list just showed up on 's front page like this:    ... which makes no sense, because the question hasn't been modified since May 25th, and the person who edited it wasn't CatLord anyway:    Turns out what actually happened was that CatLord cast a fifth reopen vote to reopen the question.    So that stamp in the questions list should probably say this instead:     reopened 4m ago CatLord 10.7k   Or just:     reopened 4m ago Change bend angle and swap node position on arrow Google calendar sharing I am a Google Apps administrator in the process of transferring a multitude of secondary calendars from a previous Google account. So following advice from  I did the following:  Old Account   Download calendar and save as ICS   New Administor Account   Create new calendar Select "Share Calendar With Others", "Share calendar with everyone in the organization - see all event details"    However nobody in the organization can see the new calendar under "Other Calendars" nor do they get any form of notification.   It seems everyone in the organization has to now somehow add this calendar(s) via "Add a colleague's calendar" OR I have to add each user's new Google account. This is turning into an administrative nightmare.  The behavior I want is:   Maintain a list of calendars that everyone in the organization has access to By default all users in organization have "See All Event Details" access. Certain organization users have "Make Changes To Events" and Apps Administrators have "Make Changes AND Sharing" As users are added/removed to the Google Apps domain the access to these calendars are automatically granted/revoked ie. Organization users should not have to do anything to get access to the list of calendars.   I am sure there is a simple solution to this that I am missing, so if someone can point me in the right direction I would appreciate it.