What to do with prehistoric experiments?

Experiments:
- [ ] "ARC". See [Kotlin-test](https://github.com/lounres/kotlin-test/tree/master/src/main/kotlin/math/varia/ARC) and [deflib](https://github.com/lounres/deflib/tree/master/ARC)
- [ ] "kosholka". See Kotlin-test
- [ ] ...