ejenk's comments

Warning to Vimperator users: some Vimperator features are currently broken in this release. See https://github.com/vimperator/vimperator-labs/issues/568

I'm sorry, but as a resident of Hyde Park for more than a decade, your experience could not be more alien to me. I have not once wished for the burden and expense of owning a car. Indeed, living here has convinced me that the personal automobile has no place in an urban environment.

Hyde Park is very far from perfect, but its problems are entirely the fault of people with attitudes like yours. You could have bought an apartment close to the shops you'd like to frequent, or bought a bicycle (and now, bike share is a legitimate option). It takes 10-15 minutes to get downtown on Metra, but you probably couldn't be bothered to read a train schedule. And indeed, the problems with Metra—namely, long headways outside of peak hours and lack of fare reciprocity with CTA—would be eminently solvable by a consituency who values freedom from cars. Instead, we have people like you, who will exacerbate our issues by demanding more parking (and hence, necessarily, less density, less walkability, less transit, and less vibrancy). The assumption that everyone will drive engenders opposition to new development, particularly the type of mixed-use development that makes things easy for people on foot.

I'm always dismayed to see this kind of thinking on a site called Hacker News. A true "hacker" would look at the problems of urban living and try to unearth the real causes instead of falling back on the same old kludge everybody uses, buying a car. If you did, you would see that the kludge itself has become the dominant problem.

You feel entitled to easy access to the city, the sort of easy access that is currently offered to drivers and prohibited to anybody else. You're coming from a place of enormous privilege. Living without a car in Hyde Park is, despite your protestations, easy. Living, with or without a car, in most of the rest of the South Side is incredibly difficult. Many people on the South Side are too poor to own a car, or are driven into poverty by needing to own one to access their jobs. By choosing to drive, you are actively making life harder for the majority of South Siders, who would benefit greatly from better transit access and jobs and shops they can safely walk or bike to. Buying a car bought you a bit of convenience, but make no mistake: the system you have bought into immiserates, maims, and kills. We need to think beyond our own immediate comforts and decide to build a city that is safe and accessible for everybody.

From the article, you'd think these ideas were invented by Coecke and Chaitin from whole cloth.

Graphical calculi for monoidal categories date back to Kelly and Laplaza (1980), with later refinements by Joyal-Street and Yetter. In incipient form, such diagrams were used by Penrose, with applications in physics, in 1971 (http://homepages.math.uic.edu/~kauffman/Penrose.pdf). The use of categorical methods in linguistics was pioneered by Lambek and can be seen as early as 1958 (http://ling.umd.edu/~alxndrw/CGReadings/lambek-58.pdf). While Coecke has done important work in these areas, it's incredibly misleading to paint these ideas as his alone.

Likewise, evolutionary algorithms have a long history, beginning at least as far back as Barricelli in 1954. Since I know nothing about Chaitin's work on this, I can't say to what extent his work is novel, but there is a vast historical context one should be aware of when talking about simulating evolution.

Surely your monoid example should be a Sigma type (`exists`), not a Pi type (`forall`), since a monoid is a specification of data for a single type A, not for all types A. Indeed, the empty type has no monoid structure, so the Pi type you wrote down is necessarily empty.

I think the author has confused NP with NP-hard (or NP-complete). Indeed, it is extremely unlikely that the unknottedness problem is NP-complete, as it is already in NP ∩ co-NP (assuming the generalized Riemann hypothesis). Furthermore, we know that the problem of computing many knot invariants is "only" BQP-complete, so it's possible that unknottedness is in BQP (i.e., efficiently solvable by quantum computers), though I don't know the expert opinion on this.