LILightMachine·Sep 18, 2026
"The developer has built an entire language around a field seemingly without realising that said field exists."
That is incredibly funny.
Here's a talk about formal verification I made 7 years ago @ DevCon:
https://www.youtube.com/watch?v=0fg1QbeeqNU
Here's Cedille Core, my implementation of Aaron Stump's self types, a Computer Science professor who taught me a lot, ~8 years ago:
https://github.com/VictorTaelin/Cedille-Core
I also implemented Kind-Lang 5 years ago, way before LLMs:
https://github.com/higherorderco/kind
I dropped out of Federal University of Rio de Janeiro to study this subject independently, because I was passionate about it, and I spent nearly 10 years doing so, daily, on weekends. That's what I do.
Bend proofs being verbose has nothing to do with me not knowing that inference, unification, or program search exists. Kind
Read the rest
had these, 5 years ago. In fact, I've also been researching the later, and I built SupGen, which overperforms every published symbolic program synthesizer in the literature by 10x or so. This is unpublished yet, but you can find my posts about it 2 years ago on X (I'm @VictorTaelin).
So, why is Bend verbose???
Because it makes it fast. It is intentional. It is my vision that a good proof language should be fully explicit, because this reduces proof-checking time significantly. That is what makes Bend realistically 10x-100x faster than every alternative.
But wouldn't that mean it is much harder to write it?
No. As you said it yourself, we have tools that can fill these proofs today! Not just AI models. You can apply these tools to produce Bend proofs, while the language itself remains a thin, dumb proof kernel that does one thing, and does it well.
If nobody is reading these proofs (because they're written by AI and automated tools), then, it is, in my opinion, irrelevant, as proofs will eventually become a layer nobody looks at, just like generated assembly.
Of course, I could be wrong here!
But it is misleading, if not just a bit malicious, to claim I "vibe-coded" a language without knowing about a field I've spent a decade researching about.
Every single part of Bend is an intentional choice I made after considering every alternative. I use LLMs to fill code after I make all hard architectural decisions because they type faster than me, and I'd rather spend my time doing useful experiments than typing trivial functions, even though I could.
Incidentally, deciding what I should NOT include took me way more time and effort than any line that was shipped, and there are perhaps millions of lines of code, manually written by me, that I threw away, backing up these 4k that went into the final design. An artist once told me you must first paint a Rembrandt before you can draw a cartoon that's simple in the right way, yet that might mislead someone who has never drawn into thinking you don't know what you're doing. I guess.