I've been using them for months since they was first announced in September. And I'm happy -- even a little relieved -- to report that Apple didn't ruin a good thing here. In fact, there's one area where I didn't realize it was even possible to make them better, but they are. Additionally, new features enhance the product's usability. Of course, there are also a couple of gaps and blind spots, and we'll talk about those, too.
Марина Совина (ночной редактор)
，更多细节参见新收录的资料
One thing that allowed software to evolve much faster than most other human fields is the fact the discipline is less anchored to patents and protections (and this, in turn, is likely as it is because of a sharing culture around the software). If the copyright law were more stringent, we could likely not have what we have today. Is the protection of single individuals' interests and companies more important than the general evolution of human culture? I don’t think so, and, besides, the copyright law is a common playfield: the rules are the same for all. Moreover, it is not a stretch to say that despite a more relaxed approach, software remains one of the fields where it is simpler to make money; it does not look like the business side was impacted by the ability to reimplement things. Probably, the contrary is true: think of how many businesses were made possible by an open source software stack (not that OSS is mostly made of copies, but it definitely inherited many ideas about past systems). I believe, even with AI, those fundamental tensions remain all valid. Reimplementations are cheap to make, but this is the new playfield for all of us, and just reimplementing things in an automated fashion, without putting something novel inside, in terms of ideas, engineering, functionalities, will have modest value in the long run. What will matter is the exact way you create something: Is it well designed, interesting to use, supported, somewhat novel, fast, documented and useful? Moreover, this time the inbalance of force is in the right direction: big corporations always had the ability to spend obscene amounts of money in order to copy systems, provide them in a way that is irresistible for users (free, for many years, for instance, to later switch model) and position themselves as leaders of ideas they didn’t really invent. Now, small groups of individuals can do the same to big companies' software systems: they can compete on ideas now that a synthetic workforce is cheaper for many.，这一点在新收录的资料中也有详细论述
由此看来，大脑感知时间，并不是靠一只“钟”，而是靠动作、动作产生的感觉以及大脑对这些感觉的关注程度共同组成的一张“网”。，更多细节参见新收录的资料
Poincaré half-space model. Take the open upper half-space \[\mathbb{H}^n := \{(x_1,\dots,x_n)\in\mathbb{R}^n \mid x_n 0\}\] equipped with the Riemannian metric whose components on the coordinate tangent vectors are \[g_{ij}(p) \;=\; g_p\!\left(\frac{\partial}{\partial x_i}\bigg|_p,\; \frac{\partial}{\partial x_j}\bigg|_p\right) \;=\; \frac{1}{p_n^2}\,\delta_{ij}.\] Geodesics are semicircles (or rays) orthogonal to the boundary hyperplane \(\{x_n = 0\}\).