DigitalTurk

Correct me if I'm wrong, but I believe this will soon no longer be true for Google Calendar. They're dropping CalDav.

Actually, I guess he's right.

Arguably, the common sense definition of 'A -> B' is simply modus ponens. That is 'Given A and A->B, it follows that B'. It's then no longer obvious that A -> B is equivalent to ~A v B.

Indeed, implication in IL is different from material implication even though IL has modus ponens.

That looks correct to me.

Actually, at first I thought it was incorrect because you used De Morgan's law, which I mistakenly thought was invalid in intuitionistic logic. However, I looked it up and apparently only ~(p & q) |- ~p v ~q is invalid in IL.

The law of excluded middle is not sufficient for proof by contradiction. What you actually need is ex falso quodlibet (principle of explosion).

For instance, paraconsistent logic has the law of excluded middle but not ex falso quodlibet.

https://en.wikipedia.org/wiki/Principle_of_explosion

https://en.wikipedia.org/wiki/Paraconsistent_logic

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addendum

Specifically, notice that in classical logic the axioms law of excluded middle and law of non-contradiction can be substituted for one another (they are equivalent). However, that is not the case for all semantics.

> Kenehora. You are zazen. Everyone should be you. You sound like a true bootstrapper, a self-made man that needs no help from others.

Actually, that doesn't sound like me at all! I have benefited from need-based grants and a cheap education system. And even despite these great conditions I almost screwed up my education several times. It took some time for me to get my act together!

> It is within your rights to offer this grant. But I see no reason why your sexist bullshit should be advertised without complaint at Hacker News.

Apparently you think this is (i) sexist but (ii) within their right to do. That's unusual… even if you believe this, why would you bring it up?

> Do you feel comfortable about traditional "old boys networks", the existence of such were one valid reason that women's groups protested men's only clubs, men's only dining rooms, etc.?

This is so over the top—I don't know what to say. My understanding is it's still mostly men who attend Hacker School.

It's like a group of men saying 'fuck, we turned into an old boys network. let's give out grants to gifted women so they can join us'. And here you—a man—are protesting outside.

> They why do you perpetuate sexism within the industry?

Is sexism against guys a problem in the industry now?

Or do you think this will increase sexism against women too? If so, you should have argued why that's the case (or at least mentioned that that's what you mean).

> I have a similar aged nephew and a niece that would benefit from Hacker School, but you will only enable one of these people to attend.

I'd love to attend but I find it too expensive. I'm not complaining about this grant though. I think it's great! I absolutely hate that there are few women in the IT industry in the Western world.

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addendum

> Either your students need financial aid or they don't.

I think this misses a point. Hacker School is throwing opportunities at people. That's awesome because people need opportunities to succeed in life. However, Hacker School does not have an obligation to give opportunities to everyone—that's just not possible. What they are doing with these grants, however, is identifying a group that has trouble succeeding in the IT industry in the Western world (most female programmers I know are Chinese) and throwing extra opportunities at this group. That's awesome because if this group is underperforming then the most obvious way to fix that is to throw extra opportunities at them!

In fact, there's an argument that the very reason they're underperforming as a group in the first place is because they have trouble identifying opportunities in the first place. E.g. because they're told girls don't have the right kind of brain for IT, because they feel intimidated by the men IT, etcetera. All the more it makes sense to give extra grants for women!

oh. Thanks.

It's not a problem when using 'clj' from the command line.

Here are some other issues I ran into (FWIW):

- println works, but print doesn't. - I was expecting cmd+A and then cmd+enter to evaluate everything. - Why are there (seemingly) no shortcuts for the command bar? - Activating 'Make current editor and instarepl' twice in a row, clears all the text in the editor… that's weird - The text cursor got confused at some point

But I guess it's an alpha version. :)

It just so happens that I started playing with Clojure yesterday! I didn't quite manage to get anything to work in LT, however.

E.g. if I do Cmd+Enter on a definition, I get this:

  clojure.lang.Compiler$CompilerException: java.lang.RuntimeException: Unable to
  resolve symbol: defn in this context, compiling:…

If I click 'Make current editor and instarepl' I get errors like this:

  clojure.lang.Compiler$CompilerException: java.lang.RuntimeException: Unable to
  resolve symbol: subs in this context, compiling:(NO_SOURCE_PATH:9)

It's all rather confusing. Maybe there's a manual somewhere I should read, but I couldn't find it.

Here's a gaffe.

The author says that Belgium has large 'Flemish' and French speaking populations, but then when he talks about Brussels he says there are large Dutch and French speaking populations.

In at least one table he lists Dutch and Flemish separately.

Is he suggesting that Dutch speakers in Brussels and Dutch speakers in Flanders really speak a different language? :-D

> "You can find families that live right next door to each other, have exactly the same education levels, exactly the same income and even exactly same religion.

However, because they speak a different language they might have gone to different schools, have a different sense of humor, watch different TV channels, read different newspapers, and be interested in the events or culture of different countries.

Moreover, in a few of the countries listed the different language groups tend to live in different regions, which can have very different economies.

I'm pretty sure it was native. I think they had hotspots for IPv4 and IPv6.

This was 6-12 months ago by the way. I imagine they might have tightened security since, with the party congress and all that.

One researcher at Peking University once told me that he uses IPv6 to access YouTube. As far as I could tell, it was available to all students and staff. Just a simple matter of selecting the right Wi-Fi network. :)

The Verge has more pictures.

http://www.theverge.com/2013/2/21/4013480/google-chromebook-...

It looks an awful lot like a Macbook: Just witness the aluminum-like color and the black bevel around the screen. Where it looks different, it's uglier. The hinge looks particularly bad. And judging by the pictures it's an awful lot bulkier than a Macbook Air.

Chrome OS strikes me as an underpowered OS. That is, there's a lot it won't do and it seems mostly suitable for underpowered machines.

UPDATE: this paragraph is wrong; I stand corrected! -- The ChromeBook Pixel has a 4:3 display. Now, I recently came across an old laptop of mine that had a 4:3 display and it looked off. I'm not saying that 4:3 aspect ratio a bad choice in an objective sense, but it strikes me as a bad choice from a marketing point of view.

For one hundred dollars less you can get a 13" Macbook Air. For two hundred dollars more you can get a 13" Macbook Pro with Retina Display. Both these machines seem better than the Chromebook Pixel in every way, including battery life (7 hours versus 5).

In conclusion, I think this is going to fail badly.

> Internal Server Error

So is your web server.

A watch shaped like a bracelet and easily removable. That very much suits my intuition of what an iWatch would be.

I have a pet theory that, when removed, the iWatch will be flat and it will be possible to use it as a phone by holding up to your ear. The cellular technology will be in your iPhone Maxi or iPad. The importance of such a feature is simply—but not unimportantly—that this would look less dorky than holding up a 5" phone to your head or using a bluetooth headset.

Well, you don't have free press (the ST is a joke) and you're not allowed to criticize politicians by name. I don't know if it's a police state, but it definitely isn't a free country either.

> Error establishing a database connection

Seems like the author's blog is starving too.

Looks interesting.

The idea seems to be that Firebase is all the server back-end you need. I can see how that could work for many applications.

On the other hand, as applications grow I can also see how you might arrive at a point where you do want to run code on a server. Is it possible to access a Firebase database from the server-end of things?

thanks. that looks interesting.

Does anyone know if this supports (efficient) graph-rewriting?

I'm thinking of this kind of patterns:

If there are nodes n and n' such that

  - there's an edge from n to n' and

  - n has a label XY

then add label Y to n'

So what I'd want to do is match basic patterns and then add nodes, edges, and labels.

Eh. Is Richard M. Stallman teaching philosophy of science now or something?

Arguably, the rough idea is to discover and prove interesting or useful facts.

> Similarly, before Dropbox we had options like XDrive from AOL, WebDAV servers, FTP, iDrive from Apple, and many others. We were awash with crappy software to store our documents on a server and access them from any computer we were on.

Amen! Don't be too hard on third-party vendors, though. Dropbox could only have been created after file-monitoring APIs became commonplace in OS kernels. If I've got my history straight these APIs were introduced because first Apple (Sherlock, Spotlight), then the GNOME guys (starting with Eazel's Medusa), and later Microsoft (after WinFS failed) wanted to do nearly-near-time full-text indexing. I remember that in Linux land these APIs were quite contentious and it took several iterations before they got them right.

I'm not sure if the ideas underlying Dropbox were _that_ unique at the time, but their execution sure was exceptionally good.

Still, some companies _were_ in a position to invent Dropbox before Dropbox did. The obvious ones being Apple and Eazel, since they had products that were monitoring the entire user file system _and_ they were selling WebDav storage!

> 1. Most countries speak different languages

Yes, and in some countries people speak more than one language. It's worrisome that Amazon is having such difficulties dealing with such a simple matter.

Additionally, there are a ton of English speakers in the eurozone and Amazon is doing a bad job in serving them. Here's one more example: Amazon.co.uk actually has a feature where you can pay in euros. However, it only works on check-out. When browsing the website you cannot have it show prices in euros. I'd shop a lot more often at Amazon.co.uk if they showed prices in euros!

> 2. The laws around selling books are CRAZY in Europe. Each country has different laws about how books are priced. FR and DE are fixed price (everyone sells the book for the same price), IT I think is Reseller (normal model, publishers sell to Amazon, Amazon sells to consumer), and UK is Commissionaire (Tax included Agent model, Amazon gets commission for selling books to consumers, but publisher sets price) and Reseller.

But you only have to abide by the system in the country you're shipping from, right? So what's the problem again?

> 3. Each country has different publishers for the marketplace, with different requirements in terms of metadata etc.

I don't understand what you mean.

Are you talking about translations of books? Those, of course, are different products from the original.

Also, some electric appliances are often sold under different brand names, but, again, in such a case we're talking about different products.

Or were you referring to something else entirely?

Well, it's a conjecture. The stock price is sky-high and this should mean that investors expect Amazon to grow much, much larger. International expansion seems to be the best way to go about that.

For the long-term survival of Amazon it might also be a good idea to try to dominate everywhere. In every market that Amazon doesn't serve, a competitor will take its place. There's a danger that in the long run such a competitor will become large and efficient enough to compete with Amazon in Japan, UK, Europe, or even the US.

Here's what I don't get. Amazon seems to be all about growth; in fact, their stock price is so high that its investors seem to believe that Amazon intends to expand enormously internationally and that it will crush all of its competitors when it does.

However, to this casual observer it seems they haven't made grounds in new markets in ages. And they're not at all a raging success in all of the markets that they have entered.

I'll give two examples.

China. They absolutely botched this. Chinese people just don't shop there. Worryingly, Amazon doesn't seem to know how to react. E.g. some time ago they started using this new Z.cn branding, but now they're just inconsistently using both the Amazon.cn and Z.cn names. (And of course they have a Chinese name also.)

Europe. For some reason they have three different stores in Europe. Two of those are in France and Germany. These stores charge in euro, which would be convenient for other Europeans except that these stores don't have English language front-ends. As such they only serve a limited market. The third store is located in the UK. It charges in pounds, which makes it a hassle to shop there. Moreover, they have weird restrictions on what they will and will not ship internationally and you have to pay by credit card—which relatively few Europeans have.

I recently read that Amazon is going to launch Amazon.nl in the near future. I've been hearing those stories for ages now, though, so I don't know if it's true. But suppose they did. Is it really a given that they will do well? In the many years that Amazon didn't open a Dutch store, tons of web stores have sprung up, and some of these have gained significant mindshare. I reckon it will be very costly and time consuming for Amazon to beat these competitors. Why is it that investors don't seem to be worried about this?

Well, I think the trick is the find meaning in small things and not to worry too much (all of the time) about how what you do fits in the grand scheme of things. Because, indeed, things that are meaningful on a small scale might be absurd when you put them in a bigger context.

So I don't see a contradiction here.

Of course worrying about what things mean on a larger scale can be virtuous, but you also want to come to terms with your limitations as a human being in a specific context.

Well, I'm happy it would only work for up to a year. Otherwise I'd be afraid that parents would inject their children with these vaccines—you know, 'for their own good'.

As a rule, I prefer traveling on my own. That way I can take my time to walk wherever I want and get a better 'feel' for the city. For instance, I love to go out into the city without a map sometimes. I often even go out of my way to eat in cheap, dirty places because I want to know what the locals eat. Sometimes I even go out of my way to explore the boring and the ugly parts of town.

It's difficult to find travel partners that share these interests. :)

Additionally, when I'm traveling with someone else I get distracted by conversations. That means I fail to notice tons of things. Also, I have experienced that my travel companion(s) would take me to all sorts of interesting places and then afterwards I'm unable to pinpoint on a map where I've been. That kind of sucks.

It's also much easier to start interesting conversations with locals or other travelers when you're not in a group.

I'm never lonely. I often stay in hostels so I can usually talk to other solo travelers. And sometimes I hit couchsurfing.org and meet up with individuals or groups.

Yum!

Orion Blaster!

I don't want to reveal my K5 nick but I'm happy you're still around. :)