thebzax

I don't know if you're being pedantic, or what exactly.

The definition of infection on wikipedia is "An infection is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to the infectious agents and the toxins they produce."

The infection killing patients is not "the coronavirus". The coronavirus is a particular kind of virus, specifically known as SARS-CoV-2. COVID-19 is, by definition "an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)". So to be pendantic, COVID-19 is the infection that is killing patients. The question of, by what mechanism the particular disease causing agents are producing the deadly reaction, is in fact is perfectly described by the headline.

My preferred term is "47 kilofeeters"

Icahn owned a bunch of Lyft stock before the IPO.

Lyft, as a company, issued new shares in an IPO. As is standard practice for an IPO in which the company issues new shares to raise money, Lyft required all of existing stockholders to agree not to sell stock on the public market for the next 6 months. So for 6 months, the shares trading under the "LYFT" ticket, will represent only those shares sold by Lyft to public market investors, and then passed on from one public market participant to another. After 6 months, all shares will be equal, and early investors and employees can sell their shares.

Icahn couldn't sell his shares on the public market. But he was allowed to sell shares in a private transaction (to an accredited investor, with all the usual qualifications for a private stock sale). The only relevant restriction Lyft imposed was that Icahn get his buyer to sign a similar agreement with Lyft, under which Soros can't sell those shares for the same six months.

The restriction is actually a little stronger than just not selling those pre-IPO shares. They also aren't allowed to engage in any financial maneuvering which in any way has some of the effect of selling pre-IPO shares.

But Soros didn't mind. By the time he bought the shares from Icahn and signed onto the agreement not to sell them, he'd already sold them! Well, he'd made what was effectively a binding agreement to sell that many shares of Lyft, at a price to be determined immediately after the IPO, but with the shares and money not changing hands until 6 months later! This is exactly what the lockup agreement prevent you from arranging once you have the shares.

The agreement Soros made was something like:

"I bet that Lyft stock will be lower in 6 months than it is next week. If it goes up I'll pay you 10 Million times the amount it goes up, and if it goes down then you pay me that instead. And the bank said sure, as long as you pay us a small fee upfront, win or lose."

So in six months, when the lockup ends, Soros will sell 10 million shares on the public market, and if that is above the post-IPO price, he'll pay the excess to the bank. If it is instead below the IPO price, the bank will pay him the difference. So he's effectively locked into the post-IPO price.

that sounds like the exact opposite of a zero-knowledge proof: https://en.wikipedia.org/wiki/Zero-knowledge_proof

There's a paper from just a couple years ago about turning hanabi (with >2 players) into a variant of the 100-prisoner hat color problem: http://helios.mi.parisdescartes.fr/~bouzy/publications/bouzy...

For the 5 player variant specifically, the concept is as follows: Out of the 8 moves each other player can make (play any of 4 cards, discard any of 4 cards), you figure out the best move, add them up mod 8, and make one of 8 hints (you have a color or number hint available for each player). Then each of the 4 other players deduces which move you wanted them to make by subtracting out everyone else's best move. There's some room for improvement on figuring out how to avoid one player mistaking another's best play (because it might be predicated on them playing a card they don't know they have first), or how to hint in ways which avoid that.

A friend has put up an implementation up on github: https://github.com/chikinn/hanabi/blob/master/players/hat_pl...

The question is more about what kinds of distributions are in some sense "reasonable" for this setup. A uniform distribution for wine/water is problematic because it implies a non-uniform distribution for water/wine, and it is reasonable to expect that these distributions should be the same.

The underlying problem is still underspecified, and there is a class of distributions which have the appropriate symmetry, as described in the paper. The range of possible answers is still more limited under this symmetry assumption (that the ratio of water/wine and wine/water should have same distribution) than under no assumption (in which case any probability between 0 and 1 is acceptable).

Unfortunately, not quite. Note from the blog post that "Since P sits in BQP which sits in PSPACE we can't prove outright any separations for BQP without separating P from PSPACE". We still haven't proven P isn't equal to PSPACE.

What BQP does efficiently solve, which classical computers do not, is a particular "Promise Problem" of the form "Input X is either of type A, B, or C, please classify it as either A or B". The promise is that I won't give you any inputs of type C, but you don't know how to tell if I break the promise.

Note also that

> "In particular, it has been shown there exist languages A and B such that P^A=NP^A and P^B≠NP^B (Baker, Gill, and Solovay 1975). The fact the P = NP question relativizes both ways is taken as evidence that answering this question is difficult, because a proof technique that relativizes (i.e., unaffected by the addition of an oracle) will not answer the P = NP question. Most proof techniques relativize."

from https://en.wikipedia.org/wiki/Oracle_machine#Complexity_clas...