the_french

Joined 14 years ago

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283
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100
Member since
Feb 12
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Comment · 4 years ago
I've talked to Yannick quite a lot in the past as my lab develops Why3 and SPARK uses my translation for their new support for pointers (access types).

Additionally, my advisor collaborates with them on counterexample generation, especially with managing to get readable counterexamples out from the SMT. We've toyed a little with invariant generation but its very tricky to get something actually usable. Additionally, I have the personal (soft) requirement that the generated invariant should be injected into the source code and not purely internal / hidden.

Comment · 4 years ago
I already do, my tool produces WhyML modules from Rust crates. But we can leverage Rust's ownership typing to drastically reduce proof obligations related to pointers and memory.

Incidentally, I've started working on a VSCode frontend to Why3 to replace the existing GTK one (https://github.com/xldenis/whycode), I'm currently rewriting the PoC as an LSP extension.

More broadly in the context of a Frama-Rust, much like Frama-C Why3 would be one of many possible backends. I specifically want abstract interpreters, test generation and other analyses to integrate and co-operate to solve proof obligations.

Ie: abstract interpretation could infer a loop invariant which is then used by a deductive backend to prove the function contract. Or a deductive failure could produce a counterexample which is transformed into a test case automatically.

Comment · 4 years ago
That kind of software is not usually written in Rust (or Ada), but using Simulink / SCADE or other model-based and synchronous tools, afaik.
Comment · 4 years ago
That’s my long term plan, I’d like to build something like Frama-C (https://frama-c.com/) but for Rust, but verification tools are not like other development processes and it’s not easy to piece them together.

I think that the first step is to develop a shared specification language for Rust, one that eventually could even become official like SPARK for Ada, then we move forward on integrating tools into a platform.

Comment · 4 years ago
This is exciting! I've met with people from AdaCore and Ferrous systems (individually) several times and they're all serious, competent and motivated.

I'm curious what kinds of software they want to (eventually) verify, my PhD thesis is developing a verification tool for Rust (https://github.com/xldenis/creusot) and I'm always on the look out for case studies to push me forward.

The road to formally verified Rust is still long but in my unbiased opinion looking quite bright, especially compared to other languages like C. Ownership typing really, really simplifies verification.

Comment · 4 years ago
> But we know how that goes and nobody actually will care about the scooter enough to return or take care of it.

Looking at countries like the Netherlands this is not true. Train stations have rentable bikes which are always available in sufficient quantities.

> So what do we do? Uber-Tesla-Subway pods. I call it by phone, it shows up to my house, either transfers me or lets me dock with the subway and then brings me the last mile just to leave me there for the next thing it has to do.

Individual 'pods' will just never be a sufficiently scalable & ecologically friendly solution for any real city. There's just no way that having several hundred kilos of metal & plastic per individual, along with the space requirements (esp for safety) works.

On the other hand, autonomous & shared 'cars' could replace individual vehicles for hauling / transporting as peak usage would be much lower than for transit.

Comment · 4 years ago
no, it isn't. Don't go around spreading FUD, the article makes no mention of causation for the deaths, extrapolating that to an entirely hypothetical (and unfounded) vaccine induced immunodeficiency is unjustified.
Comment · 4 years ago
GDPR fines can go up to 4% of global revenue so the 62 cent comparison seems apt.
Comment · 4 years ago
if I recall correctly, the fine scales up as time goes on up some (2?) percentage of company revenue. Like most people I would be happier seeing them get a several billion dollar fine right off the bat but so long as it eventually becomes unbearable that's good enough for me.
Comment · 5 years ago
I don’t think most theoretical physicists are seeking wealth, they tend to have deeper intellectual motivations.
Comment · 5 years ago
This is an interesting idea but is there any description of the soundness of this approach? Any functionality capable of subsuming not just inductive types but higher-inductive types is going to be very subtle. I looked around on the repository but I can't find any formal description of the language or type theory, which is worrying for a proof tool.
Comment · 5 years ago
> Some programs in the Simply Typed Lambda Calculus [^1] have no type—i.e. diverging programs.

Nitpick, because those programs have no type they are not members of the Simply Typed Lambda Calculus but only of the underlying untyped calculus

Comment · 5 years ago
The french government has actively promoted the growth of forests / their management for over a century. Today, there are more acres of forests than at the turn of the twentieth century for example.
Comment · 5 years ago
from the cursory read of the documentation on the openbsd site it doesn't seem to support TPMs. Setting up the encryption of a disk paritition does seem easier though.
Comment · 5 years ago
On some fronts it even feels like things have regressed. Trying to resize an encrypted partition is way, way too difficult. And it seems like GParted doesn't handle LUKS so you're back to manually typing block offsets on the command line.

If you wanted to use a TPM to store the FDE passphrase, well, you have the patience of a saint. Compare this to Mac or Windows where you click a single button and it's all setup, including TPM!

As much as I love linux for server environments, it remains a failure when it comes to modern desktop environments.

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