In the end I implemented a solution using asserts for checking uniqueness and the number of solutions. However, I got different results using maplist and concurrent_maplist, see the post Difference in success between maplist and concurrent_maplist
In the end I implemented a solution using asserts for checking uniqueness and the number of solutions. However, I got different results using maplist and concurrent_maplist, see the post Difference in success between maplist and concurrent_maplist