September 2017 - Pharo-users

Re: [Pharo-users] Pharo 7 license question

by Jimmie Houchin

On 09/21/2017 09:47 AM, Ben Coman wrote: > [SNIP] > Its horses for courses.Â No one viewpoint fits all circumstances. > Another way to look at it is that permissive licenses give a developer > more freedom to combine libraries with different licenses. > > I do like this radical simplification I bumped into... > "Another way of looking at it is that youâre picking a license based > on what you are afraid of. > * The MIT license is if youâre afraid no one will use your code; > youâre making the licensing as short and non-intimidating as possible. > * The Apache License you are somewhat afraid of no one using your > code, but you are also afraid of legal ambiguity and patent trolls. > * With the GPL licenses, you are afraid of someone else profiting from > your work [or profiting off end-users] (and ambiguity, and patent > trolls)." > [https://exygy.com/which-license-should-i-use-mit-vs-apache-vs-gpl] > > ...which aligns squarely with Pharo - our greater fear is people not > using it. I think the GPL one looks right. Fear, anger, offense if someone has the possibility of using their software and not contributing back. To me I think it doesn't work as much as they think. It doesn't take into account the free will of people to walk away and completely not use their software. I personally don't even look at GPL licensed sources unless there are none other available which is very rare. I don't want the knowledge or understanding of that code tainting other code I write. MIT often means, we don't care, do what you want, just don't blame us. We don't care if you take it and use it in closed source proprietary money making big corp software. We don't care if you take it and use it and keep it to yourself. We don't care ... Just don't blame us for any problems. However, we would love your buy in on open source philosophy and contribute back where you are able. We understand you have software which is business critical, proprietary and can not be open sourced. We also know that you probably have software which has no business specific (your business) code which is releasable. And we see many, many, big and small businesses doing so today. Close off what you must, open what you can. I don't think most of us are afraid of no one using our code. PostgreSQL has no such fear. SQLite which is public domain has no such fear. And we could go on and on. Python, etc... I personally am very much in the camp of I want people to contribute because they want to contribute. Not because I have a stick called the GPL. But rather because I have the carrot of all of the benefits derived from open source software. I am carrot oriented, not stick oriented. Jimmie

Sept. 21, 2017

Re: [Pharo-users] PetitParser Mystery

by Sean P. DeNigris

Peter Kenny wrote > I would expect the parser which fails to also > fail, for the same reason, if the input is just 'John Smith' without the > 'Jr'. Correct! It did. Peter Kenny wrote > The top-level construct in your parser is PPSequenceParser, which works in > a > simple-minded way; it just checks whether each of its component parsers > succeeds. If one of them fails, the whole sequence fails; it does not try > backtracking. Ah, okay. That makes sense. It seems I just got lucky in that when I've done this before, it was the special case you mention below of unique tokens Peter Kenny wrote > firstName, ((middleName, lastName)/ lastName), generational optional That worked for all interesting cases. Peter Kenny wrote > If you are going to produce a parser which copes with all the vagaries of > people's names, especially outside the US, I think you will have some fun. Ha ha, no doubt. I am not presuming to capture the whole domain, just an interesting - and thankfully very limited - subset! Thanks for all the help :) ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Sept. 21, 2017

Re: [Pharo-users] Pharo 7 license question

by Ben Coman

On Thu, Sep 21, 2017 at 3:57 AM, Jose San Leandro <jose.sanleandro(a)osoco.es> wrote: > Hi, > > I was afraid this would hijack the thread, and didn't want to. > No worries. Its pertinent to the topic. Licensing is a bit arcane and various viewpoints are useful. I support FSF ideals (I have a hardcopy of Stallman's book [ http://a.co/aso0v7W] and believe the GPL is appropriate for a lot of software - particularly off-the-shelf / end-user oriented software, but less appropriate for bespoke software written under contract for a specific company, (e.g. their business web site) which is the market Pharo is hoping its user-developers succeed. [ http://ballardchalmers.com/2016/03/27/bespoke-software-outgunning-off-the-s… ] I don't like these metaphors, and my attempt to answer your question may be > better, or less obvious, but I think "viral" and "infection" only describe > the GPL when your mindset does not care about the freedoms the GPL tries to > preserve. > The essential MIT/GPL license differences is how they treat free-riders and downstream user rights. You seem concerned with the latter, which is why the GPL is suited for end-user / packaged / off-the-shelf software. But Pharo's user-developers don't control the views of the companies they contract to, and forcing the GPL as the only licensing option may have a chilling effect on the ability gain engagements. So the Pharo mindset is to preserve the freedom of its user-developer's to negotiate the terms of their contracts with their clients. >From that position, what makes the GPL viral is the clause "You may convey a work based on the Program ... provided that you ... license the entire work, as a whole." So I have the freedom to distribute an application combining three libraries with separate MIT, BSD and Apache licenses while maintaining those original licenses. But add a GPL library, and now my application must distribute the other three libraries also under the GPL. Thats viral. > I'd say "effective against people trying to restrict the rights the GPL > defends" instead of "viral". > Sorry to be glib, but viral is a lot simpler (for those of a certain mindset). > The "infection" interpretation comes from the idea that the GPL restricts > freedom, which is a trap. We may be used not to care about certain rights, > or think they are secondary or even worthless. Then, when the GPL forces us > not to restrict those rights, and we still don't care about what the GPL is > trying to protect, we can conclude the GPL is a dangerous infection that > restricts our freedom of choice. > GPL is a mechanism to defend users. Software vendors used to limit users' > rights obviously get their "rights" limited. The GPL does not respect the > right to restrict others' rights. > Its horses for courses. No one viewpoint fits all circumstances. Another way to look at it is that permissive licenses give a developer more freedom to combine libraries with different licenses. I do like this radical simplification I bumped into... "Another way of looking at it is that youâre picking a license based on what you are afraid of. * The MIT license is if youâre afraid no one will use your code; youâre making the licensing as short and non-intimidating as possible. * The Apache License you are somewhat afraid of no one using your code, but you are also afraid of legal ambiguity and patent trolls. * With the GPL licenses, you are afraid of someone else profiting from your work [or profiting off end-users] (and ambiguity, and patent trolls)." [ https://exygy.com/which-license-should-i-use-mit-vs-apache-vs-gpl] ...which aligns squarely with Pharo - our greater fear is people not using it. > > Anyway, I'm not here to judge. MIT may be the most convenient license for > Pharo nowadays. I'm not discussing that. I just couldn't remain silent > thinking there's an obvious consensus that GPL is "viral" or an "infection" > and that should be avoided at all costs. > cool. cheers -ben > > 2017-09-20 21:30 GMT+02:00 Jimmie Houchin <jlhouchin(a)gmail.com>: > >> Hello, >> >> As the person who initially used the word viral in this thread, let me >> ask you a question. >> >> Personally I greatly dislike the GPL and variants. I and many believe >> viral is what describes that nature of the GPL. However, I recognize that >> there are reasonable people who like the GPL and greatly like that aspect >> of its license. It is viral and does infect. It is seen by many people >> something to avoid, just as one would avoid a virus or infection. Yes these >> are negative terms. >> >> You protest our use of these terms but do not offer alternatives that you >> prefer. In the absence of acceptable alternatives that GPL proponents >> prefer, then we left to terms that we naturally gravitate toward using. So >> let me suggest that when you make your opinion heard, please include what >> you would prefer. Otherwise it doesn't really help you with your expressed >> desires of us not using said terminology. >> >> So my question to you. What words would you use instead of viral and >> infection that equally describe that characteristic of the GPL and variants? >> >> Thanks. >> >> Jimmie >> >> On 09/20/2017 02:10 PM, Jose San Leandro wrote: >> >> Nothing to add to the particular question, but I'm writing to express how >> much I disagree when you use adjectives such as "viral" or nouns such as >> "infection" to describe GPL. >> >> I'm a FSF supporter for a long time, and while I'm used to people >> choosing not to use free software licenses for the sake of reaching as many >> business opportunities as possible, I care about the ethics behind the free >> software movement. >> >> I respect people not caring about that fundamental part of the Free >> Software movement, but I cannot remain silent when everybody seems to share >> the same unfortunate interpretation of what the GPL is about. >> >> 2017-09-17 18:59 GMT+02:00 Ben Coman <btc(a)openinworld.com>: >> >>> On Sun, Sep 17, 2017 at 7:00 PM, stephan <stephan(a)stack.nl> wrote: >>> > >>> > On 17-09-17 06:59, Jimmie Houchin wrote: >>> >> >>> >> And the GPL not be viral in my app provided I only use the GPL >>> library and am not modifying it in my app. >>> >> >>> >> Do I understand this wrong? >>> > >>> > >>> > Yes. With GPL everything is now GPL. With LGPL, as long as you only >>> link to it, >>> > the viral aspect is limited to the library. In Pharo, that means you >>> can use UFFI >>> > to connect to LGPL libraries, and you can probably create plugins. >>> Loading >>> > smalltalk libraries that are LGPL is not exactly the same as linking, >>> there is >>> > no clear boundary between compile-time and run-time, as everything is >>> in the image. >>> > That makes the LGPL difficult to interpret in the smalltalk case, and >>> potentially viral. >>> >>> +1. >>> >>> >>> On Sun, Sep 17, 2017 at 6:09 PM, Hilaire <hilaire(a)drgeo.eu> wrote: >>> > Regarding porting GPL software, I guess you mean rewriting with >>> Smalltalk, >>> > you should be free to license it as you want, for example as MIT. >>> > AFAIK there is no evil restriction as "seen the code" under the GPL. >>> >>> It is not as clean as that. Many consider "seen the code" to >>> implicate "derived code". Whether a court of law agrees with this or >>> not is not what you should consider. The best advice I received from >>> a lawyer is that winning in court (sometimes after years of effort) is >>> still a loss, so you should position yourself so that no one even >>> thinks they can take you court. >>> >>> >>> > For library, alternative is LGPL and I read this interesting note: >>> > One should note that subclassing a Java (or other OO) class licensed >>> under the LGPL is regarded as a use of an interface of a library comparable >>> to a function call of a library. It is not regarded as a modification of >>> the original class. Therefore the subclass does not fall under the >>> requirements of the LGPL. >>> >>> The definitive reference of Java + LGPL is >>> https://www.gnu.org/licenses/lgpl-java.en.html >>> which says: "The typical arrangement for Java is that each library an >>> application uses is distributed as a separate JAR (Java Archive) file. >>> Applications use Java's âimportâ functionality to access classes from >>> these libraries ... The LGPL permits this distribution ... >>> Applications need only follow the requirements in section 6 of the >>> LGPL" >>> >>> but a Smalltalk Image runs foul of section 6 requiring... "A suitable >>> [shared library] mechanism ... that (1) uses at run time a copy of the >>> library already present on the user's computer system, rather than >>> copying library functions into the executable" where an Image is >>> considered to be the "executable". >>> >>> So incorporating LGPL Smalltalk code into an Image causes all code in >>> the Image to be infected with the LGPL. >>> >>> >>> > So using a LGPL library, even extending it, does not force the user to >>> be in the GPL family license. >>> >>> Using LGPL C libraries is fine and doesn't infect your Smalltalk code. >>> Using LGPL Smalltalk libraries does infect all Smalltalk code in your >>> Image. The concern is contributing a bug fixed in Pharo code from an >>> infected image technically infects the whole of Pharo - although you >>> are free to update a clean image with the same bug fix and contribute >>> from there - but thats an awkward process. >>> >>> >>> > The only restriction is the receiver should be capable to update >>> > the LGPL package independently of the application using the package. >>> > Anyway, I don't think you should worried about porting GPL/LGPL >>> libraries as long >>> > as your are rewriting it. You can license it under MIT. Then LGPL is >>> also possible. >>> >>> The term "port" clearly implies "derived" so you cannot arbitrarily >>> re-license just by changing implementation languages. Otherwise for >>> example a GPL library could be relicensed by one team porting from C >>> to Python, then a second independent team ports from Python back to C >>> subverting the original copyright. >>> >>> >>> =============== >>> Hmmm... actually refreshing myself with the newer license texts just now >>> I notice GPL 3 has added some interesting definitions the GPL 2 lacks... >>> >>> > The âCorresponding Sourceâ for a work ... does not include the work's >>> System Libraries >>> > >>> > The âSystem Librariesâ of an executable work include anything, other >>> than the work as a whole, that >>> > (a) is included in the normal form of packaging a Major Component, >>> > but which is not part of that Major Component, and >>> > (b) serves only to enable use of the work with that Major Component, >>> or to implement a >>> > Standard Interface for which an implementation is available to the >>> public in source code form. >>> > >>> > A âMajor Componentâ, in this context, means a major essential >>> component >>> > (kernel, window system, and so on) of the specific operating system >>> (if any) >>> > on which the executable work runs, or a compiler used to produce the >>> work, >>> > or an object code interpreter used to run it. >>> > >>> > A âStandard Interfaceâ means an interface that >>> > ... is widely used among developers working in that language. >>> >>> which seems to open the door to a strong argument** that Pharo is such >>> a Major Component protected from even a full GPL3 coded application >>> being loaded and run - i.e. you could fix and contribute Pharo code >>> directly from such an Image - but other non-GPL Smalltalk libraries >>> you mix in may not be similarly protected. But it still seems a grey >>> area with compliance easier to manage using nonCopyLeft licenses. >>> >>> cheers -ben >>> >>> ** You'd probably want the FSF to directly issue a statement on this. >>> >>> >> >> >

Sept. 21, 2017

Re: [Pharo-users] (no subject)

by Christophe Demarey

Hi Ben, Could you test it with the bleedingEdge version of the launcher to see if the problem is solved? Thanks, Christophe. > Le 20 sept. 2017 Ã 08:26, Ben Coman <btc(a)openinworld.com> a Ã©crit : > > > > On Wed, Sep 20, 2017 at 1:12 PM, Ben Coman <btc(a)openinworld.com <mailto:btc@openinworld.com>> wrote: > On Thu, Sep 14, 2017 at 8:25 PM, Christophe Demarey <christophe.demarey(a)inria.fr <mailto:christophe.demarey@inria.fr>> wrote: > > Hi, > > > > I published an update of the Launcher yesterday fixing some issues to run > > Pharo images from Linux. You can find latest-versions (0.2.13) here: > > http://files.pharo.org/platform/launcher/ <http://files.pharo.org/platform/launcher/> > > It already propose to download Pharo 70 images. The VM is now downloaded > > automatically if the adequate one is not available. > > Let us know if everything is fine. > > Thanks Christophe for updating PharoLauncher. I'm trying it with Pharo 7 images for the first time. > I hit a problem using Iceberg in downloaded images. > > $ unzip Pharo-linux-0.2.13.zip > $ cd pharo > $ unzip ../PharoLauncher-user-stable-2017.09.14.zip > $ ./pharo > + PharoLauncher > Settings > Enable development environment > + World > Tools > Iceberg > ==> iceberg opens okay > + PharoLauncher > Templates > Pharo 7.0(beta) > latest-32 <Create Image> '7latest32' > + '7latest32' <Launch> > + World > Tools > Iceberg > ==> "Error: EXternal module not found" > > $ uname -a > ==> Linux 3.16.0-4-686-pae #1 SMP Debian 3.16.7-ckt25-2 (2016-04-08) i686 GNU/Linux > > > but this works okay... > $ curl get.pharo.org/70+vm <http://get.pharo.org/70+vm> | bash > $ ./pharo-ui > + World > Tools > Iceberg > ==> iceberg opens okay > > > while this PharoLauncher alternative fails... > $ curl get.pharo.org <http://get.pharo.org/> | bash > $ ./pharo-ui > + World > Tools > Catalog > PharoLauncher <Install stable configuration> > + World > PharoLauncher > ==> Doesn't show Pharo 7 templates > + World > Monticello > ...PharoLauncher/main <Open Repository> > + ConfigurationOfPharoLauncher-ChristopheDemarey.56 <Load> > + World > Playground > "ConfigurationOfPharoLauncher load" <DoIt> > + World > PharoLauncher > Settings > Hard reset persistant state > ==> Pharo 7 templates showing > + '7latest32' <Launch> "i.e. the previously downloaded image" > + World > Tools > Iceberg > ==> "Error: External module not found" > > + World > Monticello... load latest mczs... > * PharoLauncher-Core-ChristopheDemarey.123 > * PharoLauncher-Spec-ChristopheDemarey.51 > + '7latest32' <Launch> "i.e. the previously downloaded image" > ==> "Fetching VM to run Pharo 70 images" > + World > Tools > Iceberg > ==> "Error: External module not found" > > > Version comparison... > > direct get.pharo.org/70+vm <http://get.pharo.org/70+vm> > /home/ben/Pharo/adhoc/Pharo7/Pharo.image > Pharo7.0alpha.build.132.sha.4ea2f39a9f43185d31b844be5ad33b677f43bf17 > /home/ben/Pharo/adhoc/Pharo7/pharo-vm/lib/pharo/5.0-201708271955/pharo > CoInterpreter VMMaker.oscog-eem.2265 uuid: 76b62109-629a-4c39-9641-67b53321df9a Aug 27 2017 > > via PharoLauncher... > /home/ben/Pharo/images/7latest32/7latest32.image > Pharo7.0alpha.build.132.sha.4ea2f39a9f43185d31b844be5ad33b677f43bf17 > /home/ben/Pharo/vms/70-x86/lib/pharo/5.0-201708271955/pharo > CoInterpreter VMMaker.oscog-eem.2265 uuid: 76b62109-629a-4c39-9641-67b53321df9a Aug 27 2017 > > Must be something environmental in lookup paths. Can you reproduce or suggest further investigation I can do? > > cheers -ben > > > > >

Sept. 21, 2017

Re: [Pharo-users] (no subject)

by Christophe Demarey

> Le 21 sept. 2017 Ã 13:25, Stephane Ducasse <stepharo.self(a)gmail.com> a Ã©crit : > > Christophe > > which version should we take? For now, the bleeding edge. I will publish a stable as soon as it gets tested enough.

Sept. 21, 2017

Re: [Pharo-users] (no subject)

by Christophe Demarey

> Le 20 sept. 2017 Ã 23:36, Stephan Eggermont <stephan(a)stack.nl> a Ã©crit : > > On 17/09/17 05:21, Sean P. DeNigris wrote: >> demarey wrote >>> Let us know if everything is fine. >> Was this issue [1] fixed: >>> I think I found it. It seems to be a bug in the way Launcher/Pharo unzips >>> the downloaded VM. >>> The symlink libgit2.dylib becomes unlinked and appears as just a regular >>> file. If I delete the >>> Pharo.app and unzip 70.zip (which btw maybe should have been deleted >>> during cleanup after >>> the dl) to ./vms/70, the error disappears! > > With todays bleedingEdge PharoLauncher on mac I was able to download and start 60510. When trying to load GToolKit > > Iceberg enableMetacelloIntegration: true. > Metacello new > baseline: 'GToolkit'; > repository: 'github://feenkcom/gtoolkit/src'; > load. > > I ran into some problem with libgit2 that I could solve by doing the unzipping of the downloaded vm zipfile with the Archive Utility and replacing the vm (and re-adding the sources). I tried to reproduce the problem with the same configuration without success. It works well. I guess you already downloaded the required VM with a previous version of the launcher (using Pharo unzipping). If you delete this VM and use the launcher to run the image, it should download the VM and uses your system unzip command to extract it.

Sept. 21, 2017

Re: [Pharo-users] (no subject)

by Stephane Ducasse

Christophe which version should we take? Stef On Wed, Sep 20, 2017 at 12:17 PM, Christophe Demarey <christophe.demarey(a)inria.fr> wrote: > Hi Sean, Stephan, > > I just updated the PharoLauncher and it should now work fine for 64-bits images. > I just had time to test it roughly but you can give it a try (https://ci.inria.fr/pharo/view/Launcher/job/Launcher/149/) > > Christophe. > > >> Le 20 sept. 2017 Ã 10:52, stephan <stephan(a)stack.nl> a Ã©crit : >> >> On 20-09-17 08:26, Ben Coman wrote: >> >>> Must be something environmental in lookup paths. Can you reproduce or suggest further investigation I can do? >> >> If I understand it correctly it is a problem with the unzipping. Not handling symlinks and preserving permissions. Is that a plugin problem? >> >> Stephan >> >> > >

Sept. 21, 2017

Re: [Pharo-users] PetitParser Mystery

by PBKResearch

Sean I'm not an expert on PetitParser, but I think I understand what is happening. If I am right, I would expect the parser which fails to also fail, for the same reason, if the input is just 'John Smith' without the 'Jr'. If this is not so, you can disregard the rest of this post. The top-level construct in your parser is PPSequenceParser, which works in a simple-minded way; it just checks whether each of its component parsers succeeds. If one of them fails, the whole sequence fails; it does not try backtracking. (You can see the code at PPSequenceParser>>#parseOn:) In your case, the second component parser, which is 'middleName optional', succeeds, because 'Smith' could be a middle name. The next component, 'lastName', fails because 'Jr' is not a valid last name, but there is no way for the sequence parser to recall that the previous component had an optional element. So the sequence fails. The only way to cope with this that I can see is to make the options explicit by using the slash, which does show the parser where to backtrack to. This is what your second parser does. You could limit the scope of the backtracking to avoid re-parsing the first name, by writing something like: firstName, ((middleName, lastName)/ lastName), generational optional (I'm not sure whether the innermost parentheses are necessary, but at least they do no harm.) Thinking about this, I wondered how 'optional' could ever be used except at the end of a sequence. I think the answer is that it works if the optional token has a format or structure which identifies it uniquely if it does occur; in this case, the effect of 'optional' is to say 'forget it if it doesn't occur'. In your case, there is nothing to distinguish a middle name from a last name; indeed, I believe in US usage they can be the same - if Jane Smith marries John Doe, can she become Jane Smith Doe? If you are going to produce a parser which copes with all the vagaries of people's names, especially outside the US, I think you will have some fun. Many people in France would write a surname like yours with a space after the 'De', and probably a lower-case 'd' as well. In Scotland, a suffix like 'Jr' could appear as 'the Younger'. Some people have more than two forenames. Some people have double-barrelled surnames, with or without a hyphen. Those are just a few of the complications I can think of. So good luck! Hope this helps Peter Kenny -----Original Message----- From: Pharo-users [mailto:pharo-users-bounces@lists.pharo.org] On Behalf Of Sean P. DeNigris Sent: 21 September 2017 03:18 To: pharo-users(a)lists.pharo.org Subject: [Pharo-users] PetitParser Mystery Given: generationalPart := (#space asParser, generational) ==> #second. middleName := (#space asParser, (generational not, abbreviatableToken) ==> #second) ==> #second. lastName := (#space asParser, (generational not, token) ==> #second) ==> #second. and input := 'John Smith Jr'. The following parser fails: abbreviatableToken, middleName optional, lastName, generationalPart optional. But this one succeeds: (abbreviatableToken, middleName, lastName, generationalPart optional) / (abbreviatableToken, nil asParser, lastName, generationalPart optional) They look the same to me. What is the difference? Thanks! ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Sept. 21, 2017

PetitParser Mystery

by Sean P. DeNigris

Given: generationalPart := (#space asParser, generational) ==> #second. middleName := (#space asParser, (generational not, abbreviatableToken) ==> #second) ==> #second. lastName := (#space asParser, (generational not, token) ==> #second) ==> #second. and input := 'John Smith Jr'. The following parser fails: abbreviatableToken, middleName optional, lastName, generationalPart optional. But this one succeeds: (abbreviatableToken, middleName, lastName, generationalPart optional) / (abbreviatableToken, nil asParser, lastName, generationalPart optional) They look the same to me. What is the difference? Thanks! ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Sept. 21, 2017

Re: [Pharo-users] (no subject)

by Stephan Eggermont

On 17/09/17 05:21, Sean P. DeNigris wrote: > demarey wrote >> Let us know if everything is fine. > > Was this issue [1] fixed: >> I think I found it. It seems to be a bug in the way Launcher/Pharo unzips >> the downloaded VM. >> The symlink libgit2.dylib becomes unlinked and appears as just a regular >> file. If I delete the >> Pharo.app and unzip 70.zip (which btw maybe should have been deleted >> during cleanup after >> the dl) to ./vms/70, the error disappears! With todays bleedingEdge PharoLauncher on mac I was able to download and start 60510. When trying to load GToolKit Iceberg enableMetacelloIntegration: true. Metacello new baseline: 'GToolkit'; repository: 'github://feenkcom/gtoolkit/src'; load. I ran into some problem with libgit2 that I could solve by doing the unzipping of the downloaded vm zipfile with the Archive Utility and replacing the vm (and re-adding the sources). Stephan

Sept. 20, 2017