Enfin un article qui dénonce les horreurs auxquels j'ai été confronté de plusieurs manières :
«La maltraitance médicale est encore trop fréquente»
sante.lefigaro.fr
19 oct 2016
24 nov 2016
For news of Syria, here is a news site made by Syrians
Manju Sambander 22 jan 2017
Data rescuing or theft?
Time has come that world should re-define the word "Theft".
Very appropriate timing..
Hackers downloaded US government climate data and stored it on European servers as Trump was being inaugurated
28 jan 2017
Mafia médicale et médecine de consommation
bon-coin-sante.com
Le système de santé entretien les gens malades de façon réfléchie et organisé. Gouvernement mafieux, laboratoires gangster et médecins lobotomisés.
13 fév 2017
Des choses qui ne m'étonnent pas en comparaison de ma propre expérience des hopitaux :
Bordeaux : la femme amputée des 4 membres après une IVG raconte son calvaire
9 mars 2017
For the second time in a short period I lost access to my account just because of absurd "security" algorithms that "fear" that my account "might be at risk" and under that excuse, inactivate it until it get restored after a correspondence with the FB staff (the only way I finally do because the "normal" way by identifying pictures of friends is exhausting and not reliable). If another time I don't reply it might be for the same reason, so it is more reliable to write me by email
Jordan Ess > INTP™
29 juin 2017· Breckenridge, États-Unis
(...)
link to article : I'm Irish and I spent a year traveling the US — here are the 17 things that surprised me about day to day life
Oliver Rosten
3 aout 2017
Hopefully there are people in a position to effect real change who are listening.
A paper on field theory delivers a wake-up call to academics
Oliver Rosten believes the postdoctoral system played a role in his friend’s suicide. Disseminating that opinion in a scientific journal took perseverance.
https://physicstoday.scitation.org/do/10.1063/PT.6.2.20170803a/full/
28 aout 2017
Yesterday my account was disabled and I could not restore it quickly because the "security" procedure was bugged. Then I complained about it to the support, and today the account is restored (not sure why: because of my complaint or because I connected from a place I had used in the past... it skipped the security checking, directly to the question where I confirmed that the "suspicious" connection was mine)... so it is okay but the repetitive joke of frequent account disabling in the name of "security" while it is always only me connecting from different place they decide to see "suspicious" is getting really tiring... just in case, please also try writing me by email if I seem to not read messages here.
9 nov 2017
Mike Huemer
Bryan Caplan’s book, _The Case Against Education_, is out:
https://www.amazon.com/dp/B076ZY8S8J/.
(Libertarian scholars like to bite the hand that feeds them. J Brennan is also evidently working on a book designed to undermine higher education.) I read Bryan’s ms. in progress, and it was excellent – very clear, compelling, and interesting.
Thesis: The economic value of education is mainly due to signaling.
Explanation: Education pays off for students because getting a degree signals to employers that you have certain desirable traits, such as intelligence, perseverance, and the ability to follow instructions. It’s not that college *gives* you those traits; it’s just that those who lack them don’t complete a college degree. College generally does not teach useful skills.
Evidence: Caplan reviews a ton of scholarly evidence, which is collectively very compelling. I can’t summarize it here. But a few interesting observations:
(a) Education is one of very few products where the buyer doesn’t seem to want it. If you cancel class, the students aren’t angry; they’re happy. For what other product would the customer be happy if they didn’t receive it? The evidence is that students don’t want to be educated; they’re not paying for knowledge.
(b) Students hardly remember anything they learn in a typical college (or even high school) class. Six months after the class is over, they’re going to have forgotten most of what the course was about. (Exception: basic reading and arithmetic skills.) This is widely recognized. So it can’t be that the economic value of schooling is due to the valuable information one learns.
(c) Just look at a typical college class. We teach all kinds of obviously impractical subjects. (Exceptions: engineering, business.)
(d) A favorite claim of educators: “We don’t teach people what to think; we teach them *how* to think.” Problem: there is virtually no empirical evidence that we actually succeed in doing this. People in educational psychology have studied “transfer of learning”: roughly, the extent to which students transfer lessons they learned in one context to a slightly different context; that is, the extent to which their learning generalizes to make them better at tasks they weren’t explicitly taught to do. The results are generally negative: transfer of learning typically just does not happen, as far as we can measure. Given this, the idea that we make people generally better at thinking is only a wishful assertion.
And that is how the claims on behalf of education generally are: hopes with no empirical support. Everything that we can measure says that schooling is (with a few exceptions) ineffective, so wishful defenders of schooling move to claims of unmeasurable, unobservable benefits.
(e) Statistically, almost all of the economic value of schooling accrues *at the end*. If you complete 3.5 years of your degree program but don’t get the degree, you get little economic value (little increase to your expected earnings). You get the big bump in earnings when you get the diploma. This is hard to square with the theory that the economic value of education is due to learning useful information and skills (do colleges wait until the very end to confer the useful information and skills?).
Implications:
(a) More education won’t obviously increase productivity for society. Getting a degree increases your earnings, not by making you more productive, but merely by enabling you to outcompete other candidates for a job. If everyone gets more schooling, that will just raise the bar for what you have to do to edge out other candidates.
(b) It doesn’t really matter (to the economic function of schooling, or what the students are really paying for) *what* we educators teach, or how well we teach the material. We only need to make it sufficiently challenging that it qualifies as a test of general intelligence, perseverance, and similar traits. (Whew! that makes me feel better.)
My comment: Most of the above is summary of Caplan (except implication b above, which I think I added). But I think Caplan makes a powerful case. We educators, for obvious reasons, would not *like* to believe all this. But we should fight against our own biases to try to evaluate the argument objectively.
8 dec 2017
Trying to extrapolate the recent rise of value of Bitcoin into future trends, it seems to be on a divergent curve about to reach infinity in finite time, which may be as early as the next couple of weeks. But the next value after +infinity is logically -infinity, which in logarithmic scale means zero. So, be careful !
Seriously, some time ago I explained some troubles I see with Bitcoin here and I did not change my mind since then : http://settheory.net/future/Bitcoin
Some recent news:
Founders of hacked crypto-mining site apologize over Facebook livestream
Steam ends support for bitcoin
Bitcoin mining consumes more energy than 159 countries
Man who ‘threw away’ bitcoin haul now worth over $80m wants to dig up landfill site
26 jan 2018
I just found some very strong evidence of the reality of extrasensorial perception during OBE: the case of Nicolas Fraisse. Most of the stuff is in French, sorry for those who don't understand it, I only found this link in English :
Nicolás Fraisse – translation of interview with researcher
Some videos in French :
https://www.youtube.com/watch?v=npbrm1n5aZQ
https://www.youtube.com/watch?v=DdZSswf22lg
11 fev 2018
Another scientific evidence, namely of the power of mediums to receive information from dead people related with a witness who is completely hidden (they cannot see nor hear), so as to exclude any kind of mentalist tricks. The video is in French, including an interview, translated from English, about scientific research from the Windbrige institute, who have scientific publications (http://www.windbridge.org/for-researchers/), establishing the reality of supernatural reception of information; the reporter reproduced the protocol in even stricter conditions (totally blind) as shown from minute 16, and got similar concluding results: https://www.youtube.com/watch?v=if0ArgnrtwU&t=2393s
17 fev 2018
Now about Artificial Intelligence. Some people miss the fact that my convictions are rooted in such deeper, more general and reliable theoretical analysis, that any seemingly challenging observation in current fashionable news (which seems very compelling to the crowd), is to me quite futile. Aside the case of Bitcoin I mentioned earlier (I do believe in the possibility of a future revolution of finance by internet but NOT in the form of a cryptocurrency as usually assumed), the recent fuss about Alpha Zero appears to strengthen the field of Artificial Intelligence. Still I remain unimpressed. Again while I do believe that IT can change the world and that AI has a nice potential, I know precisely what IT advances can make the biggest change but that does NOT involve AI, and there will NOT be any technological singularity in the sense usually expected. The ideology of AI, if I didn't miss something, suggests that we should be on the verge of the Singularity just if 2 conditions are met : the availability of high enough computing power, and some design of a highly intelligent software has been found. Now that both conditions are finally met, I no more see an excuse how, following the AI thesis, the long promised Singularity could still fail to come in the next decade or two. But I'm confident it won't come anyway, even if, of course, AI can nicely contribute to economic growth. Let's wait and see !
5 fev 2019
New page :
On the philosophical treatment of dualism
27 fev 2019
One more review of widespread nonsense in philosophy :
A mathematician's response to the philosophy of mathematics
8 mars 2019
Yesterday my access to facebook was temporarily disabled because the facebook system detected "suspicious activity". I do have some intense activity and sometimes move to a different place, which the Facebook system does not seem very tolerant of : it does not seem nomads-friendly ! I wish I could notify in advance the next place where I go, to ask it to not be suspicious when I will connect from there, but there is no such option ! The SMS from Facebook no more reach me in the last months (while those from Gmail still do). In the past I had experience of failing to identify pictures of friends, which is a very bothering kind of exam. This time I succeeded at this test, but maybe I'm lucky. Then Facebook made me change my password and review the recent activity which it suspected of having been not mine. All this activity was mine ! so I had to change my password while no reason exists to suspect it to have been stolen ! Please take note of my email (trustforum at gmail.com) to be sure to stay in touch with me in case the problem re-occurs ! thanks
And the problem re-occurred for longer, which got me very worried, so I wrote a new page http://settheory.net/facebook-security-hole
29 mars 2019
Once more I was denied access to my account, just for logging in from a different place, no matter that this new place is where are the events I had saved in advance in my account. As I had foreseen the risk of this, I had cared to save the list of all people to whom I had written in the last 2 weeks, since that is the only question among security procedures for which I can reliably prepare to answer, in the list of those which were offered last time this happened. However this procedure no more appeared in the list of possibilities !!!! Instead, was the possibility to be approved from a recent place of connection. To follow that procedure I had to SEND BY EMAIL MY LOGIN AND PASS to someone who seemed honest but who I did not really know, who was at the place of that recent connection (I had not his direct contact, the message went through 2 other people before him). HE HAD TO CARE ABOUT IT AND CHANGE THE PASSWORD and send it to me FOR 3 SUCCESSIVE TIMES. Now absurd is that : it is supposed to be in the terms and conditions of Facebook that one should never give one's password to anyone else, yet I was obliged to do so by the Facebook security procedures themselves ! now connecting with a new password which THE OTHER PERSON created for me.
Mohamed Elfatih Hady
This is one bad aspect of Facebook security procedures! However, you succeeded to login again to your account.
· Répondre
· 2 ans
Manju Sambander
You need to go thro your settings and check whether this is on:
"extra security" for alerts about un-recognized logins. Each time you change locations, you will be receiving an "email alert". Once you get this alert, you are expected to login as usual, check the inbox and confirm. If you avoid the alerts, FB will have to freeze your acccount temporarily.
So, If you change locations very often, then you have been given two options:
i) You may set "OFF" for alerts (No more extra security)
ii) or attend all email alerts for some time and let FB keep the records of all locations.
I hope this would be the best remedy.
Here´s a sample scr- shot. ..
Sylvain Poirier
Now the same trouble appears to be happening to one of my contacts who lives in China. Yeah in China due to the Great Firewall it is necessary to use a VPN, which means appearing to be connecting from different places other than one's real locations, which Facebook will never stop seeing as "suspicious". Poor Chinese people who try to use Facebook... of course they will keep preferring their home made online networks under government control in such conditions...
19 avril 2019
Given the current international news I could not do without adding to my site a page on black holes :
http://settheory.net/black-hole
It remains short (quickly done); I have another topic I want to focus on, to put online hopefully after a week or so.
25 avril
Now one of my contacts has the same problem I had several times : the account being "temporarily disabled" under excuse of "requiring a verification" http://settheory.net/facebook-security-hole
That is someone living in China, thus having to use a VPN to access Facebook. What is the sense of finding necessarily "suspicious" the fact of "connecting from another place" when that "place of connection" is whatever proxy the VPN will use ? Poor Chinese people, especially non-geeks not ready to struggle with technological hazards, in the face of this monster of infinite Facebook wickedness suddenly treating people like shit, making them waste time and nerves in vain with these absolutely stupid nonsensical games maliciously designed to do everything to playfully deny the recognition of users identity ??? I had tried to argue with that contact for the use of Facebook vs. the Chinese, government-controlled WeChat social network, with the idea of risk of censorship with WeChat. But now my argument is being defeated : the risk of troubles (discontinuation of services) appears much higher with Facebook than with WeChat. I'm on the edge of being convinced I should rather use WeChat now.
10 mai 2019
In the French news, one case comes out about a surgeon who committed a lot of horrors. I am not surprised. It is actually very common for surgeons to do horrible things, and there is usually no way to stop them, as I suffered some mistreatment myself and there has never been any way to provide any feedback to stop such things from happening. If there was no usual green light and impunity for surgeons who commit horrors, it would not be explainable how it could take so long to stop this one.
Affaire du "chirurgien de l'horreur" à Grenoble : 80 personnes s'estiment victimes du praticien
12 mai 2019
Some improvements done to my presentation of the logical nonsense of naturalism - still not perfect.
The logical nonsense of naturalism
16 mai 2019
Just completed a slides version of my introduction to quantum physics and its interpretations http://settheory.net/quantum-philo.pdf
26 mai 2019
As I explained years ago in my videos "why learn physics by yourself", the trouble with trying to force young geniuses to keep following the academic system up to PhD is that it is hardly more intelligent than the idea of trying to climb Mount Everest : not only it is extremely hard and dangerous (for the risk of resulting suicide), but it does not even make someone exceptional.
Traffic Jams on Everest: Ethical or Not?
http://settheory.net/learnphysics
6 juin 2019
New text I just finished :
Acting for the climate
30 oct 2019
Finally my page of introduction to the incompleteness theorems which I recently developed as second complement page to Part 1 is now essentially ready (I still have to make the French version and revise the third complement page).
Still doing a few reworks, especially I just divided it in 2 pages (1.B. Truth undefinability ; 1.C. Introduction to incompleteness).
....
30 nov 2020 Finished updating part 2 in both English and French
27 dec 2019
From the news: report of natural disasters of 2019 due to climate change
Counting the cost 2019: a year of climate breakdown
4 avril 2020
I am currently working to write a long criticism of the ideology of skepticism. This now includes and expands my remarks from previous posts on the clash between D Raoult and our medical authorities, which comes as a remarkable illustration of this clash between both quite different conceptions of "science". Yet this page remains far from finished as many other points, unrelated with these current world news, are yet to be written...
http://antispirituality.net/skepticism
7 mai
This work progressed a lot but remains unfinished. It is now in 3 parts, the first 2 have been revised to be near final form, I still have to complete the 3rd part.
24 mai
More progress done, now about 73 pages ready, minus 2 pages of redundancies for the French+English versions of some quotes from videos at the end of Part 2. One section added to the first part "A possible libertarian solution to some controversies" much reworked and expanded with side comments compared to my Facebook post on this topic. There remains a bit more than 2 sections to write, for an expected total of about 80 pages.
16 juin
Done. About 90 pages total.
4 sept On the terrible new Facebook interface. There was something which worked, somehow. Well I'm not claiming that it really worked. Only that it was relatively usable, in a world of people generally so stupid that since the beginning of the Web, while thousands of benevolent programmers and greedy startupers passionately undertook to try making alternatives (maybe also thousands of alternatives, most often 1 or 2 programmers for each), still nothing much better was created (only a few other systems reached success, often with quite similar conception by lack of imagination). After about 1 decade of that "success", Facebook is changing itself. But I don't mean to call it a real change either. A big news for a very superficial change in a dumb world where usually nothing happens.
So they think they had good ideas how to change themselves, just like thousands of other developers thought they had good ideas how to create something better but which most often turned out to be worse. They may think that they understand how to make something better, just because they happened to make something better than others at first. They don't see that they were actually just as stupid as others, so that if their first stuff worked somehow it was more based on chance than on proper thinking. And that if you once won the lottery, it does not make you more likely to win it a second time than those who didn't.
I don't like the new interface. Not only it lost some of the little bits of convenience the previous interface had, it brings new bugs, and, well, they claim to invite users to bring feedback but I don't believe they will take proper lessons from these, just like they almost never cared about any user feedback.
As the proverb says "if it ain't broke, don't fix it".
(I first wrote this comment in my site before copying it here).
I keep switching back to the classical interface because the new interface just does not work in some ways. I hope many people do the same so the Facebook staff will understand they must keep the old interface available.
In particular, an events search in the new interface can have much fewer results than in the old one. Precisely it gives the beginning of that list as it appeared in the old interface until some point. I have no idea what determines that point.
Irina Le
The bugs of the new version have been horrible; for many posts likes and/or shares are not even shown; I wonder what kind of algorithm could cause such a bug. Their feedback service sucks as well.
18 sept Disaster. I cannot switch back to the old interface, and the new interface only gives less than 10% of events.
16 nov
Un lien vidéo trouvé par hasard (je n'ai pas pris le temps de regarder)
Surdoués, HP... - Qui sont-ils ? | Dans la tête d'un surdoué
Le syndrome d'Asperger
Découverte | Surdoués, mais à quel prix?
22 nov
New text. A small one this time.
A superiority of animals over humans
30 nov
Just finished updating my work on the foundations of maths down to the end of Part 2 (Set Theory), including the pdf version.
settheory.net/sets/
1 jan
I just completed some recent additions to my long criticism of the skeptical ideology : antispirituality.net/skepticism
I noticed during the night that the first part was recently truncated of its last third during some edit. I restored the missing end from the Nov 24 google cache. So any further references I could add since then were lost... not sure how much is that
...
2 jan
I just completed the new division of parts, and corrections of introduction + both new sections in first part.
...
11 jan
Things are running crazy as I look for references and standard terminology to define the concept of "embedding" in concrete categories. It involves a concept of "initial morphism". Usual definitions for this concept of "initial morphism" rely on the concept of "concrete category" being formalized in terms of the functor to the category of sets; therefore this concept of embedding is generalizable to the use of other functors (variants of the concept of concrete category).
https://en.wikipedia.org/wiki/Embedding
https://lup.lub.lu.se/search/ws/files/6360188/4393826.pdf
https://math.stackexchange.com/.../intuition-behind-the...
https://math.stackexchange.com/.../universal.../3975365...
(where the last, short answer is mine).
This use of the phrase "initial morphism" originally comes from the case of topology with its concept of "initial topology", generated by the pullback of the topologies by a family of respective functions to different topological spaces
https://ncatlab.org/nlab/show/weak+topology
The particular case of only one function is more trivial, as the pullback directly fits as topological structure with no need of generating something else. This function between those topological spaces is then an embedding, hence the name "initial morphism" as (almost) synonym for embedding. Now this concept of "initial morphism" for concrete categories (thus leading to the concept of "final morphism" by reversing the arrows), is re-expressible as having a particular format, that of a "universal property", a very general style of properties which has the advantage of making the thing essentially unique. But, not all authors are aware of this equivalent definition (because we need to specify relatively to what these embeddings are essentially unique, otherwise they aren't). Generally a "universal property" consists in something being formalizable as either an "initial object" or a "final object" in some other category to be specified. More precisely, our "initial morphisms" happen to be... final objects in some category. Because the universal property of "initial morphisms" is a final one, not an initial one. Now, there is also a standard description of what a "universal property" is, in some wide generality : not just that it qualifies an initial or final object of simply any other category which needs to be defined case by case, but, for any "universal property" (really ?), this other category hopefully fits some precise format for which a general description is given, in terms of..., you know what ??? these initial or final objects are re-expressed respectively as 2 concepts, abusively called in wikipedia by the same name of "universal morphisms"
https://en.wikipedia.org/wiki/Universal_property
The power of generality for these "universal morphisms" to represent "any universal property" comes from the fact their definition depends on some choice of functor, which is thus what remains to be specified for each "universal property" we can consider.
This expression in terms of "universal morphism" is explicitly given for the construction of the initial topology in Wikipedia
https://en.wikipedia.org/wiki/Initial_topology
Now the confusion of calling both "universal morphisms" is resolved elsewhere
https://renrenthehamster.wordpress.com/.../the-basics-of.../
https://math.stackexchange.com/.../does-initial-morphism...
by calling the ones "initial morphisms" and the others "final morphisms". It even seems to have been this way in a former version of wikipedia "Universal property" before, as referred to in some pages
https://math.stackexchange.com/questions/980008/relationships-between-initial-terminal-objects-and-initial-terminal-morphisms-i
https://math.stackexchange.com/questions/941539/natural-numbers-object-via-initial-morphism
https://en.wikipedia.org/wiki/Adjoint_functors
Conclusion:
There are 2 concepts of "initial morphism", and by symmetry 2 concepts of "final morphisms". Each of these concepts is defined by means of some functor. The "initial morphisms" for one definition using a given functor are particular cases of (or maybe a case of final stuff that fails to be covered by) "final morphisms" for the other definition using a very different functor.
Pedro Sánchez Terraf
Doesn't "regular mono" do the trick for you?
Sylvain Poirier
No. I accept concrete categories as a worthy concept as I want to do something relatively more introductory and less specialized than usual works on the topic, and this concept of embedding in concrete categories is the one which fits the context of what I am writing. It would be ridiculous to argue for giving up a piece of math for another just because of the mess in vocabulary for it by other authors.
Namely, some embeddings are not regular monos nor anything better than monos in abstract categories, such as the embedding of ℕ into ℤ. If something works with embeddings, there is no point to restrict consideration to regular monos.
Done, replacing "initial morphism" by "pre-imbedding". First see "Embeddings" in http://settheory.net/algebra/morphisms
then in 3.8 "Modules", then in 3.9 "Embeddings in concrete categories" and "submodules". If you need explanations for the last example "an L-system is algebraic", see 3.3.
Now wondering which notations may be good for actions and co-actions of categories. A possible idea is to follow a certain habbit of using lower indices (similar to lower star) for what goes forward to the given arrow (thus, actions) and upper indices for what goes backwards (co-actions). But the hom functor of action on morphisms from a fixed object A is an action, while a set of fuctions from A (though these are morphisms, maybe not functions) is rather an exponential which suggests to put A as upper index in this case (while it is a co-action which acts on arrows to a fixed object).
20 fev
I am now ending the presence of a Facebook like button on the front page of my site. Screenshot of the last Likes number.
10 mars
Now is another denotational problem, maybe as any denotational problem it can be seen ridiculous, but still... I do need good notations for my course.
The set of functions from A to B is written as an exponentiation B^A because when they are finite, its number of elements is the exponentiation.
For images and preimages we have the star notations, up and down
https://en.wikipedia.org/wiki/Image_(mathematics)
For hom functors we have the notations with up and down indices
https://en.wikipedia.org/wiki/Yoneda_lemma
This is coherent with the star notations, as with down position the function goes in its normal way (covariant action) while with up position it goes in the opposite way (contravariant action).
But if we have a function f from B to C then by composition with functions from A it defines a function from B^A to C^A : functions f act on functions from A in the covariant way. Therefore this action defined by the choice of A should be denoted by putting A as a lower index (f_A), while we should only put A as higher index (f^A) for the contravariant action, that is the action as a function from A^C to A^B, sets of functions to A. Such incoherences make me consider to decide, as a solution to this inconsistency, to switch up and down positions with respect to usual conventions. As the exponentiation convention for sets of functions is so solidly established (obliged by the convention for numbers), I would then need to switch the covariant/contravariant notations, as well as the star notations for images and preimages.
Actually there is another good reason to do this switch of position : it is in order to be coherent with the index notations for tensors.
Indeed, in the tensor formalism, vectors are denoted with an upper index, while covectors are denoted with a lower index. The official "reason" for this is that vectors are qualified as "contravariant" while covectors are qualified as "covariant". But actually this reason is complete bullshit : it is based on viewing vectors and covectors as packs of coordinates, and defining the "covariant" vs "contravariant" qualities as a quality of these packs of coordinates with respect to a change of basis. But all this is actually the wrong way of conceiving things, because basically, vectors and covectors are geometric objects, not packs of coordinates, so that discussing their behaviors with respect to changes of basis is irrelevant. What is relevant, is how they behave with respect to linear transformations (which are the morphisms in the category of vector spaces). In this way, vectors are covariant while covectors are contravariant.
To sum it up : the litterature denotes
Vectors x as x^i "because they are contravariant"
Covectors y as y_i "because they are covariant"
I will denote
Vectors x as x^i because they are covariant ;
Covectors y as y_i because they are contravariant.
It will be much clearer I think.
11 mars
New text http://antispirituality.net/pseudoscience
[skipped discussion]
7 avril
En Chine, les mines de bitcoins menacent les objectifs climatiques du pays, selon une étude
28 avril
While working on some last improvements to my subsection on the system ℤ of relative integers, now in English but to be later translated into French
http://settheory.net/arithmetic/integers
I just checked on wikipedia about some annoying vocabulary details, and my fear of trouble got an explicit confirmation in a footnote:
"The convention that zero is neither positive nor negative is not universal. For example, in the French convention, zero is considered to be both positive and negative. The French words positif and négatif mean the same as English "positive or zero" and "negative or zero" respectively."
https://en.wikipedia.org/wiki/Negative_number
The way I introduced ℤ essentially obliges me to use the French convention. And I see no good reason to use different methods of presentation depending on the language used. Sorry for the English speakers !
