* [on ruliology and λ-calcul](https://writings.stephenwolfram.com/2025/09/the-ruliology-of-lambdas/)
* [typechecker zoo](https://www.stephendiehl.com/posts/typechecker_zoo/)
* [A tale of 4 lambdas](https://raw.githubusercontent.com/steshaw/lennart-lambda/master/top.pdf)