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Warcraftcn/UI – UI component library inspired by classic Warcraft III aesthetics

https://www.warcraftcn.com/
1•vyrotek•50s ago•0 comments

Trump Vodka Becomes Available for Pre-Orders

https://www.forbes.com/sites/kirkogunrinde/2025/12/01/trump-vodka-becomes-available-for-pre-order...
1•stopbulying•2m ago•0 comments

Velocity of Money

https://en.wikipedia.org/wiki/Velocity_of_money
1•gurjeet•4m ago•0 comments

Stop building automations. Start running your business

https://www.fluxtopus.com/automate-your-business
1•valboa•8m ago•1 comments

You can't QA your way to the frontier

https://www.scorecard.io/blog/you-cant-qa-your-way-to-the-frontier
1•gk1•9m ago•0 comments

Show HN: PalettePoint – AI color palette generator from text or images

https://palettepoint.com
1•latentio•10m ago•0 comments

Robust and Interactable World Models in Computer Vision [video]

https://www.youtube.com/watch?v=9B4kkaGOozA
1•Anon84•14m ago•0 comments

Nestlé couldn't crack Japan's coffee market.Then they hired a child psychologist

https://twitter.com/BigBrainMkting/status/2019792335509541220
1•rmason•15m ago•0 comments

Notes for February 2-7

https://taoofmac.com/space/notes/2026/02/07/2000
2•rcarmo•17m ago•0 comments

Study confirms experience beats youthful enthusiasm

https://www.theregister.com/2026/02/07/boomers_vs_zoomers_workplace/
2•Willingham•24m ago•0 comments

The Big Hunger by Walter J Miller, Jr. (1952)

https://lauriepenny.substack.com/p/the-big-hunger
2•shervinafshar•25m ago•0 comments

The Genus Amanita

https://www.mushroomexpert.com/amanita.html
1•rolph•30m ago•0 comments

We have broken SHA-1 in practice

https://shattered.io/
9•mooreds•31m ago•2 comments

Ask HN: Was my first management job bad, or is this what management is like?

1•Buttons840•32m ago•0 comments

Ask HN: How to Reduce Time Spent Crimping?

2•pinkmuffinere•33m ago•0 comments

KV Cache Transform Coding for Compact Storage in LLM Inference

https://arxiv.org/abs/2511.01815
1•walterbell•38m ago•0 comments

A quantitative, multimodal wearable bioelectronic device for stress assessment

https://www.nature.com/articles/s41467-025-67747-9
1•PaulHoule•39m ago•0 comments

Why Big Tech Is Throwing Cash into India in Quest for AI Supremacy

https://www.wsj.com/world/india/why-big-tech-is-throwing-cash-into-india-in-quest-for-ai-supremac...
1•saikatsg•40m ago•0 comments

How to shoot yourself in the foot – 2026 edition

https://github.com/aweussom/HowToShootYourselfInTheFoot
1•aweussom•40m ago•0 comments

Eight More Months of Agents

https://crawshaw.io/blog/eight-more-months-of-agents
4•archb•42m ago•0 comments

From Human Thought to Machine Coordination

https://www.psychologytoday.com/us/blog/the-digital-self/202602/from-human-thought-to-machine-coo...
1•walterbell•42m ago•0 comments

The new X API pricing must be a joke

https://developer.x.com/
1•danver0•43m ago•0 comments

Show HN: RMA Dashboard fast SAST results for monorepos (SARIF and triage)

https://rma-dashboard.bukhari-kibuka7.workers.dev/
1•bumahkib7•44m ago•0 comments

Show HN: Source code graphRAG for Java/Kotlin development based on jQAssistant

https://github.com/2015xli/jqassistant-graph-rag
1•artigent•49m ago•0 comments

Python Only Has One Real Competitor

https://mccue.dev/pages/2-6-26-python-competitor
4•dragandj•50m ago•0 comments

Tmux to Zellij (and Back)

https://www.mauriciopoppe.com/notes/tmux-to-zellij/
1•maurizzzio•51m ago•1 comments

Ask HN: How are you using specialized agents to accelerate your work?

1•otterley•52m ago•0 comments

Passing user_id through 6 services? OTel Baggage fixes this

https://signoz.io/blog/otel-baggage/
1•pranay01•53m ago•0 comments

DavMail Pop/IMAP/SMTP/Caldav/Carddav/LDAP Exchange Gateway

https://davmail.sourceforge.net/
1•todsacerdoti•54m ago•0 comments

Visual data modelling in the browser (open source)

https://github.com/sqlmodel/sqlmodel
1•Sean766•56m ago•0 comments
Open in hackernews

Z3 API in Python: From Sudoku to N-Queens in Under 20 Lines (2015)

https://ericpony.github.io/z3py-tutorial/guide-examples.htm
155•amit-bansil•2mo ago

Comments

skopje•2mo ago
Very good to see all this in one short page!
stevesimmons•2mo ago
It's worth noting these notes are 11 years old. The first give-away was the comment that in Python 3/2 is an integer, which is indeed true in Python 2 but not in Py3.

For modern users of Z3, you'd want to do `pip install z3-solver` rather than use `Z3Py` mentioned at the very bottom of this doc.

almostgotcaught•2mo ago
https://www.hakank.org/z3/
__alexander•2mo ago
Thank you for the link.
brap•2mo ago
That’s a very clean API.
cess11•2mo ago
It's very close to the SMTLIB API.

Page 19 in https://smt.st/SAT_SMT_by_example.pdf shows an example in both Python and SMTLIB. After looking at a guide like TFA this book is a good next step.

tombert•2mo ago
Solvers are something that still kind of feel like magic to me. I have done a fair amount of Isabelle, and the "sledgehammer" tool in there (which uses solvers to see if an existing proof can be made to work to solve your subgoal) is something that impresses me every single time I use it.
nextaccountic•2mo ago
On same level of abstraction I think it's useful to view those tools as some form of constraint solving. Think how you can solve sudoku with pen and paper by writing out each possibility, then fill squares either because it has only one possibility or by making guesses. After you fill a square, you can then update your possible states (propagate constraints), and repeat until you solve it or hit an impossible solve (in which case you need to backtrack on some earlier guess).

The algorithms differ mainly in how they keep track of all possibilities and how they update them

I think this answer is pretty good https://cstheory.stackexchange.com/a/29428 (take note at the end "sat is csp on boolean domains")

tyilo•2mo ago
I have created a Python library called "z4-solver" that adds some nice utility functions on top of z3: https://github.com/Tyilo/z4

I always use that instead of the z3-solver directly.

Recursing•2mo ago
Have you tried to compare Z3 with cvc5? https://cvc5.github.io/docs/cvc5-1.1.2/api/python/pythonic/p...

It offers basically the same API and could be faster in many cases

gignico•2mo ago
I was about to comment the same. Z3 always takes all the credit but cvc5 is just as great!
raphman•2mo ago
"SAT/SMT by Example" also contains many Z3 examples (and has a new URL): https://smt.st/
philzook•2mo ago
I'm a fan. I've been building a proof assistant directly on the z3py api. https://pypi.org/project/knuckledragger/0.1.3/
gbacon•2mo ago
We care about Z3 because it is a Satisfiability Modulo Theories (SMT) solver.

Satisfiability: In 1971, Stephen A. Cook established that Boolean satisfiability, given an arbitrary Boolean formula whether an assignment to its variables exists that evaluates true, is NP-complete.

https://dl.acm.org/doi/10.1145/800157.805047

Translating between NP-complete problems is at most a polynomial (“fast”) amount of work, so every improvement gained on satisfiability (whose worst case is exponential rather than polynomial time complexity) benefits all other NP-complete problems, and thus the rest of NP.

Modulo Theories: We can think of SMT as a high-level language that automates encoding of other problems into raw Boolean formulas. Applications built on Z3 outsource search by encoding problems via one or more theories and then decoding results back to the problem domain at hand.

The benefits of doing this are (1) using an existing robust, well-tested suite of algorithms where (2) lots of research effort is concentrated and (3) improvements to Z3 improve your problem’s results more-or-less for free. According to Microsoft, “Z3 is used in a wide range of software engineering applications, ranging from program verification, compiler validation, testing, fuzzing using dynamic symbolic execution, model-based software development, network verification, and optimization.”

https://www.microsoft.com/en-us/research/project/z3-3/

See also:

https://github.com/Z3Prover/z3