mmarx

> I don't understand why you people act like you're stumped by literally, literally page 1 of computer science.

… and yet you didn't stop for a moment to consider that in a field as fast-moving as computer science, a concept which might not have had a formal definition in 1967 acquired one in the past 59 years? See, for example, Sipser's Introduction to the Theory of Computation, which has an entire section (3.3 in my 1997 print) titled “The Definiton of Algorithm”.

It's already past midnight in New Zealand, e.g.

In multi-user mode, Nix uses dedicated build users to write to the store. There is also single-user mode, but that also doesn't require a world-writable store.

> Theoretically, we could also go for finding the semantically equivalent C code. However, last time I researched, checking semantic equivalency is a very complex problem. I think it was NP hard.

Already deciding whether two finite automata decide the same (regular) language is PSPACE-complete; it's undecidable for anything that can decide arbitrary context-free languages (which C programs can clearly do).

This machine has 8 states, so (for actual Turing Machines with an unbounded tape) you'd be looking at BB(8). However, since the tape can only store 24 symbols, the machine only has 8 (states) * 4 (tape symbols) * 24 (tape length) = 768 different configurations. Thus, any program will either terminate in at most 768 steps, or loop indefinitely.

Since the model tape isn't actually infinite, this machine has a finite state space, and termination is therefore decidable. No Turing Award to obtain here …

Yes, technically you'll also get a MediaWiki instance there, but the point is really to offer Wikibase (which is a set of extensions upon MediaWiki), the software behind Wikidata.

> Before the phaseout started, nuclear contributed more than 20% to electricity generation.

That's true, but also quite meaningless. Before the nuclear phaseout started, renewables contributed less than 7% to electricity generation, now it's over 56%, so it more than compensates for the missing nuclear generations. Furthermore, replacing coal with nuclear is not easily done, since most coal plants also generate heat, whereas none of the nuclear plants did.

> Earth just experienced its hottest 12 months in recorded history and it was really incredibly poor decision making to start shutting down nuclear power plants while still burning coal.

None of the remaining reactors had usable fuel left, even just acquiring new fuel would already take 12 or more months (besides, all of the remaining reactors were already several years overdue on safety inspections). The decision to phase out nuclear power has been made well in advance of those 12 months: originally in 2002, partially pushed back in 2010, then finalised in 2011, and again pushed back (by 3.5 months) in 2022. The poor decision making is not phasing out nuclear power, the poor decision making is not also phasing out coal and pushing renewables from at least 2011 onwards.

from the linked YouTube video:

> This is the second time I've successfully tested this on a Class 800. For some reason this time I seem to have actually confused the toilet door controller enough that it decided "screw this" and went into out of order mode, which didn't happen the previous time.

So, yes, the author _did_, in fact, disable the door.

Ah, thanks, that was indeed what I was missing.

From the truth table, subtraction is clearly truth-preserving, so it cannot actually be functionally complete. What am I missing?