Re:Formal Verification Gates for AI Coding Loops
by zozbot234 on Wednesday May 20, 2026 @04:54PM
(#48213993)
> It's type system itself is Turing complete
That's not a good thing! A Turing complete type system means that compilation is potentially undecidable and non-terminating. The whole unintuitive mess in dependently-typed systems about "definitional" equality (loosely speaking, a notion of equalities that are 'trivially' checked as part of evaluation) is entirely about avoiding Turing-complete type checking!
Re:Formal Verification Gates for AI Coding Loops
by pyrex41 on Wednesday May 20, 2026 @05:04PM
(#48214109)
I mean yes, that's a risk, and you are correct. In practice, is your spec about the shape of the app you want to build really going to be that complicated?
But I mentioned its Turing completeness as a lazy shorthand to illustrate that it is far more flexible and expressive than what people think of as a "type system". https://shenlanguage.org/OSM/Recursive.html
Now, a lot of the ports haven't been maintained. But the underlying Shen kernel is only 4-5k lines of code...remains extremely portable. More discussion here https://news.ycombinator.com/item?id=39602472
I didn't focus a ton on Shen in the blog post, because the underlying principles aren't really about the implementation. Shen is very cool tho.