Hi Fabian, I just run the code again and I get 6 solutions too, because it contains duplicates (for example, 2x "astante" within one solution, which is technically correct but not very beautiful).

Unfortunaly I can't remember what I did differently last time to prevent the duplicates. (if I did). Anyway I updated the blogpost.

Basically the solution listed here is a PicoLisp implementation of this solution:

stackoverflow.com/questions/21220573/learning-pro…