Wonderings of a SAT geek

Most-linked posts?

1. MiniSat in your browser (2013)
   3 people · 3 mentions · first linked 2013-09-30
2. Computing Tricky Probabilities Using Model Counting
   2 people · 2 mentions · first linked 2025-02-09
3. How Approximate Model Counting Works
   2 people · 2 mentions · first linked 2018-12-09
4. Ganak: The making of a high-performance model counter
   2 people · 2 mentions · first linked 2026-03-01
5. Probabilistic Approximate DNF volume counting
   2 people · 2 mentions · first linked 2023-09-24

What Hacker News says?

1. zero_k · 2024-05-17

   I was involved with implementing the DNF volume counting version of this with the authors. You can see my blog post of it here: https://www.msoos.org/2023/09/pepin-our-probabilistic-approx... And the code here: https://github.com/meelgroup/pepin Often, 30% of the time is spent in IO of reading the file, that's how incredibly fast this algorithm is. Crazy stuff. BTW, Knuth contributed to the algo, Knuths' notes: http…

   Comment linking /2023/09/pepin-our-probabilistic-approximate-volume-counter

   on “Computer scientists invent an efficient new way to count”
2. zero_k · 2026-10-04

   Submitted Incentives in Academic Research as a story · 64 points

   HN discussion
3. zero_k · 2025-02-18

   But you forgot! It's also a 3-wise independent linear hashing function! Which means it can be used for probabilistically approximately uniform sampling and counting of solutions to boolean functions. This is super-duper useful. We use it to build counters that give probabilistic, but proven, counts. I explained the idea here in more understandable terms [1]. Basically, it halves the solution space approximately corr…

   Comment linking /2018/12/how-approximate-model-counting-works/

   on “XOR”
4. another · 2019-02-14

   Submitted SAT Solvers as Smart Search Engines as a story · 45 points

   HN discussion
5. zero_k · 2026-08-23

   This is very important work. If it interests you, and you want to dig further, it's broadly called "Safety II". You probably want to read Erik Hollnagel [1] or Sydney Dekker. I put together a presentation once about how this translates to IT security [2]. But broadly: Safety I Learn from Errors, Safety defined by absence,Reactive approach, Understanding what goes wrong, Accident causation models, Avoidance of errors…

   Comment linking /largefiles/safety2.pdf

   on “How Complex Systems Fail (1998)”
6. zero_k · 2025-02-10

   Submitted Computing Tricky Probabilities Using Model Counting as a story · 19 points

   HN discussion
7. zero_k · 2020-08-09

   Yes. It turns out that squeezing more performance out _purely_ from the silicon has been mostly due to: (1) hand-rolled memory layouts that optimize placement, do bit-stuffing and the like to take the most advantage of the cache, (2) using clever data structures that cache certain elements of the pointed-to data in the data we read linearly, thereby allowing the cache to pre-fetch them and allow us not to (always) d…

   Comment linking /2016/03/memory-layout-of-clauses-in-minisat/

   on “SMT Solving on an iPhone (2018)”
8. another · 2016-09-10

   Submitted CryptoMiniSat 5.0.1 released – with MIT license as a story · 5 points

   HN discussion
9. zero_k · 2018-02-13

   Wow, that's kinda interesting. I somehow cannot get rid of the feeling of having a really nice hammer and then treating everything as a nail. There are other uses of deep/machine learning that could help SAT solvers. For example, one could try to better guess the learnt clauses to keep/throw away or to restart when the search space is deemed non-interesting through prediction models built using machine learning. See…

   Comment linking /2018/01/predicting-clause-usefulness/

   on “NeuroSAT: Learning a SAT Solver from Single-Bit Supervision”
10. matt_d · 2025-02-09

    Submitted Computing Tricky Probabilities as a story · 4 points

    HN discussion
11. bainsfather · 2015-11-13

    Here's a post from 2012 titled "AMD’s OpenCL heaven and hell": http://www.msoos.org/2012/01/amds-opencl-heaven-and-hell/ Things have not changed since then. Here is the author of the book "OpenCL in Action" discussing his problems with AMD's drivers: http://www.openclblog.com/2014/10/amd-and-opencl-20.html Best quote: "dealing with fglrx is murder. I have never installed an AMD graphics driver without repeated trial…

    Comment linking /2012/01/amds-opencl-heaven-and-hell/

    on “The Expanding Ecosystem For GPU Computing”
12. another · 2019-06-14

    Submitted CrystalBall: Sat Solving, Data Gathering, and Machine Learning as a story · 4 points

    HN discussion
13. shoo · 2015-07-07

    Yup, I agree! After figuring it out by hand I was having fun encoding it for sat via this horrible pipeline: step 1 : write it out by hand in PBL [alpha] step 2 : convert it to CNF format using [beta] step 3 : hand-reformat it tediously to produce [gamma] step 4 : plug machine readable CNF into [delta] step 5 : receive a feasible solution! [epsilon] [alpha] Main_Exp : ((a <=> (b & c & d & e & f)) & (b <=> (~c & ~d &…

    Comment linking /2013/09/minisat-in-your-browser/

    on “Multiple choice”
14. matt_d · 2021-09-18

    Submitted CMSGen, a Fast Uniform-Like Sampler as a story · 3 points

    HN discussion
15. zero_k · 2026-02-04

    I still remember the time when a gcc bug caused MiniSat to output UNSAT for a satisfiable problem [1]. I was the author of a SAT solver, and I was chasing my tail trying to figure out why I was getting UNSAT for a satsifiable problem. I have to admit I didn't expect it to be a gcc bug... (note: bug was found by Vegard Nossum on the CryptoMiniSat mailing list) [1] https://www.msoos.org/2013/04/gcc-4-5-2-at-sat-compet…

    Comment linking /2013/04/gcc-4-5-2-at-sat-competition-201/

    on “Broken Proofs and Broken Provers”
16. matt_d · 2018-12-09

    Submitted How Approximate Model Counting Works as a story · 3 points

    HN discussion
17. PaulHoule · 2023-10-06

    The old A.I. is making strides on this one https://www.msoos.org/wordpress/wp-content/uploads/2011/03/E...

    Comment linking /wordpress/wp-content/uploads/2011/03/Extending_SAT_2009.pdf

    on “Research Benchmark: Can NNs break cryptography schemes?”
18. idoco · 2014-11-06

    Submitted MiniSat in your browser (2013) as a story · 3 points

    HN discussion
19. mate_soos · 2017-05-27

    Submitted Testing and Pentesting – a Rant as a story · 2 points

    HN discussion
20. kaeso · 2013-09-30

    Submitted MiniSat in your browser as a story · 2 points

    HN discussion
21. zero_k · 2026-03-02

    Submitted Ganak: The making of a high-performance model counter as a story · 1 points

    HN discussion
22. matt_d · 2026-03-01

    Submitted Ganak: The Making of a Versatile, High Performance Model Counter as a story · 1 points

    HN discussion
23. zero_k · 2023-09-24

    Submitted Probabilistic Approximate DNF volume counting as a story · 1 points

    HN discussion
24. matt_d · 2023-09-24

    Submitted Pepin: Probabilistic Approximate Volume Counter as a story · 1 points

    HN discussion

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• JJohn Regehrblog.regehr.org