Lots of trouble installing cabal on 16.04
E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages
How do natural and weapon attacks mix? I have a level 1 Synthesist Summoner.  Since he has the Quadruped base Eidolon, when fused, my Summoner has a bite attack (Primary). In addition, I have spent evolution points on a tentacle (Secondary). Finally, my Synthesist carries around an Axe, with which he can make weapon attacks.  If I were to use the Full-Attack option, what attacks could I make, and at what penalties? Let's assume I want to always use the Axe, where possible.  How does this interact with the eidolon's natural attack limit? (3 at first level) How to get cross-references to multiple figures? NSInvocation for Dummies? How exactly does NSInvocation work? Is there a good introduction?  I’m specifically having issues understanding how the following code (from Cocoa Programming for Mac OS X, 3rd Edition) works, but then also be able to apply the concepts independently of the tutorial sample. The code:  - (void)insertObject:(Person *)p inEmployeesAtIndex:(int)index {     NSLog(@"adding %@ to %@", p, employees);     // Add inverse of this operation to undo stack     NSUndoManager *undo = [self undoManager];     [[undo prepareWithInvocationTarget:self] removeObjectFromEmployeesAtIndex:index];     if (![undo isUndoing])         [undo setActionName:@"Insert Person"];      // Finally, add person to the array     [employees insertObject:p atIndex:index]; }  - (void)removeObjectFromEmployeesAtIndex:(int)index {     Person *p = [employees objectAtIndex:index];     NSLog(@"removing %@ from %@", p, employees);     // Add inverse of this operation to undo stack     NSUndoManager *undo = [self undoManager];     [[undo prepareWithInvocationTarget:self] insertObject:p                                        inEmployeesAtIndex:index];     if (![undo isUndoing])         [undo setActionName:@"Delete Person"];      // Finally, remove person from array     [employees removeObjectAtIndex:index]; }   I get what it’s trying to do. (BTW, employees is an NSArray of a custom Person class.)  Being a .NET guy, I try to associate unfamiliar Obj-C and Cocoa concepts to roughly analogous .NET concepts. Is this similar to .NET’s delegate concept, but untyped?   This isn’t 100% clear from the book, so I’m looking for something supplemental from real Cocoa/Obj-C experts, again with the goal that I understand the fundamental concept beneath the simple(-ish) example. I'm really looking to be able to independently apply the knowledge -- up until chapter 9, I was having no difficulty doing that. But now ...    Thanks in advance! C# Settings.Default.Save() not saving? Number of functions from n-element set to {1, 2, …, m} I've gotten stuck at the following exercise;     There are m functions from a one-element set to the set {1, 2, …, m}.   How many functions are there from a two-element set to {1, 2, …, m}?   From a three-element set? Give a recurrence for the number of T(n) of   functions from an n-element set to {1, 2, …, m}. Solve the recurrence.   I'm not sure how to begin solving it? Why is the Star Trek 2009 reboot called a reboot? Division ring if and only if it has no proper left ideals. "404. That’s an error." when viewing from Google cache My site is getting 404. That’s an error. message when I click on cached from Google search results.  This is the error message from Google:  That’s an error.   The requested URL /search?q=cache:8kxLAgFrhZQJ:www.mysite.com.....&amp;cd=8&amp;hl=en&amp;ct=clnk&amp;gl=uk was not found on this server. That’s all we know.  What I did before I was getting this error is that about 10 days ago, I moved my hosting from Ixwebhosting to Gearhost (cloud based). I also added 301 redirect from non www to www.  I have no idea why I am getting this error. Please advise what might be the reason if there is a solution for it.  All of my pages are indexed by Google though. How to complain about a user? I  and a user was rude to me in a comment and in an answer. Even though I can't downvote, that answer got -5 and it was automatically deleted. I want to complain about that user. How can I do that? I'm trying to watch for any new output of a log file. Another script (not under my control) is deleting the file then creating a new one with the same name. Using tail -f doesn't work because the file is being deleted. Prove that if $V$ and $W$ are three-dimensional subspaces of $\Bbb R^{5}$, then $V$ and $W$ must have a non-zero vector in common.  So far I got $V = \{v_{1}, v_{2}, v_{3}\}$ and $W = \{ w_{1}, w_{2}, w_{3}\}$ because they are 3-dimensional subspaces. Then $V \cup W = \{v_{1}, v_{2}, v_{3}, w_{1}, w_{2}, w_{3}\}$  My prof said that now I need to prove that they are linearly independent so this is a contradiction and the statement is wrong because we are in $\Bbb R^{5}$ and we have 6 elements on it.  I don't know how to express them as a linearly independent proof, so I hope anyone can give me a good explanation on it. How to prove a cross is not locally homeomorphic to an euclidean space? Consider the subset $X = \{(x, 0) \mid -1 \lt x \lt 1\} \cup \{(0, y) \mid -1 \lt y \lt 1\} \subset \Bbb R^2$. It's just two open segments intersecting at $(0, 0)$.  How do you show that $X$, equipped with the subspace topology of $(\Bbb R^2, \lvert \lvert \cdot \rvert \rvert_2)$, is not locally homeomorphic to an euclidean space because of the point $(0, 0)$ ? Why is plain-hash-then-encrypt not a secure MAC? Sylow 2-subgroups of the group $\mathrm{PSL}(2,q)$ What is the number of Sylow 2-subgroups of the group $\mathrm{PSL}(2,q)$? Can you Dash twice on the same turn? The Dash action gives you extra movement for the current turn (equal to your speed). If I have an effect (like the Expeditious Retreat spell or the monk's Step of the Wind feature) which allows me to dash as a bonus action, can I also dash as my regular action, for triple movement? Showing just color ramp in legend without values Storing datetime values in Shapefiles using QGIS? I have a shapefile with date in a string field. I create a new field with date type and use the calculator to make the conversion. But the result only provide the date part, the time part is removed. Even when the preview show the correct conversion.  Here you can see the original string field time and the result date time2. And the use of the conversion function to_datetime() and the preview result at the end    If you go to the layer properties you can change the edit mode to date/time. Then if go to the data and try to edit time2 you get the current date/time. So is possible save date and time in the same field. But the update tool still doesn't work as expected      As J.R said. Even when you can change QGIS edit to allow Date/Time the save to shapefile will discard the time. deals with various ways of rewarding the finding of duplicates, a tough and increasingly necessary janitorial task.  Here's a concrete suggestion:   Reward the finder of a duplicate with +10 points if the question gets closed as a dupe. If multiple duplicates are found, reward all finders whose suggestion was voted for at least once by another user. (The limitation is to avoid gaming by making frivolous suggestions when it's obvious that a question is going to get closed as a duplicate.) Reward each following closevoter who picks one of the previously suggested dupes with +2 points if the question gets closed. Punish everyone involved (dupe-finders and dupe-voters) with -5 points, and revoke all rep gained from the dupe-voting, if a question closed as duplicate gets reopened.   A punishment for mis-voting is going to be controversial but in my eyes, it is absolutely essential. Finding a good dupe is a work of love: You need to make sure you understand the OP's question, and you need to scan every potential duplicate for whether it really contains an answer that will help the OP. Everyone dupe-votes carelessly from time to time, so the threat of punishment needs to be present to keep everyone on their toes, just as the threat of downvoting does when you post an answer.  If you think +10 is too high a reward: Consider that finding a duplicate can often be more work than writing an answer, and a correct answer usually nets you at least 10 points, if not much more.   If you think -5 is too much of a punishment: -2 might work as well, although I really think there should be a harsh punishment on an unfair dupe-closing. Calculating geometry for feature class with x/y and Lat/Long values in different projections? How to compare two float values in ksh? To compare float values below command is working fine in bash, But not working in ksh on AIX.  if (( $(bc &lt;&lt;&lt; " 5.3 &gt;= 5.3") ));then echo "hi";else echo "bye";fi`,   I had tried in so many ways, can someone suggest me to achieve this.