My understanding is that tactics output piece of proof, but that this isn't trusted by the TCB of an LCF prover. This is very far from my area of expertise, but seems to be confirmed by https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-39.html
Wow. Glad it worked out. There were at least some good high school CS teachers in the 90s. Ours knew that a lot of kids joined the class who were burned out on school, and insisted on going beyond the curriculum to the point where those guys would have a chance at a coding job right out of school - if they put in the work. We also had to implement binary arithmetic from scratch (booleans) although I think that was in the curriculum.
I had the same problem when I was in uni. Funnily enough, the RCD switches for each block were behind a panel in the common toilets, which did not have a real lock; just a hole for a "cabinet key" (a square rod).
Right, so the problem here, apart from people not giving a shit, is that no-one has designed a 'spirit level for soundproofing' - a tool that can be used during the job by the builder and by the supervisor to check on it. What you have is equipment that can be used after "second fix", at which point no-one wants to rip the plaster off to fix anything, so it becomes a box ticking exercise.
There are two kinds of issue: a solid transmission path that shouldn't exist ('bridge'), and a gap or void that shouldn't exist. What we need is something like a time domain reflectometer but for sound conduction, so you can detect gaps and bridges after screwing on the drywall but before skimming over it, and before the doors have been put in - ie, while there's still a massive audio path a few meters away. Ideally, even if the next panel hasn't been screwed on. If you had that, then if it detects something then all you have to do is unscrew a panel to fix it, which is something that people might actually do.
Anyone who has enough audio engineering skills, feel free to build this!
When people complain about housing prices being too high, this is what I usually point them to. There are _a lot_ of boxes to tick, some of those boxes are critical, some are not so much. Some are severely punished, some are not so much. Some have extremely high costs and are a PITA, some not so much.
A project that addresses that issue is betrusted: https://betrusted.io/
Their plan for fab trust is not to bring up a fab,but to design for inspectability: https://bunnie.org/iris/
I happen to own a Precursor, and indeed used it for some experiments, but it's unfortunately limited by Xilinx Spartan-7 availability, which is one of the few FPGA's that have been reverse-engineered, and they probably don't make it anymore... Another one that has been RE'd is Lattice ECP5 but it's in the same category. I'm pretty sure you couldn't make 50 million devices like that. I know they've been looking into alternatives, but haven't caught up yet.
That's very interesting. I guess it could be a great option for when the % of ICE vehicles is low enough, it might be practical to ban more polluting fuels.
(Edited to add) Hmm actually people are already doing LPG conversions today as it's cheaper. Not sure if all LPGs are as pollution free, though.
It depends how you do it. The conversion on my elderly Range Rover is not as efficient, being an old-fashioned "single point" system - this has a thing a bit like a cooker ring attached to the throttle, a stepper motor controlled valve driven by a third lambda sensor, and a thing to disconnect the petrol injectors when it switches to gas.
You can get ones with a complete set of LPG injectors and an ECU that takes its timing from the petrol injectors, and these are incredibly efficient. They're a bit harder to install (you need to drill holes in the intake manifold, it's a faff) but the engine can be mapped for even more power than on petrol and a tiny amount of pollution.
There's still a lot of CO2 and water vapour, but as previously discussed you're burning all this shit anyway so you might as well extract useful work from it.
The time to have done this was 25 or 30 years ago, when it was ridiculously cheap to buy gas and there were a lot of old-fashioned carburettor-fed cars that were incredibly badly polluting.
My understanding is that that works for personal use. If you want to use a group library, not so much. Which can be considered fair, as mostly organisations which should be able to help fund zotero are the ones that need group libraries.
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