You can use typed Lisp, there are plenty of them, from Typed Racket to Shen in their complexity. Or to make your own type system in 50-100 lines when you actually need

Okay, so be it. I want to emphasize that the purpose of numbering has shifted from technical to marketing. For development purposes, it was better before.

Why not SemVer? It would look so simple and logical. I don't need to know the release year as an user, stability and convenience is what I looking for. I can decide, update this thing it not, just by looking at major version number, but date tells me nothing about backward compatibility