Of course you can keep balls segregated when not being weighed. Otherwise, the challenge would be hopeless. But you can't, without a change similar to one I mentioned, confidently keep balls segregated from each other on the same side of the balance across a weighing. That limitation prevents some strategies. Coding with or without that limitation will give different sets of solutions. And there is at least one initial division of balls for the first weighing of your problem that either leads to a solution or doesn't depending on whether you accept that limitation.

"All solutions to include Perl6" means only Perl6 solutions are welcome. With the comma, your sentence just doesn't make sense to me. :) Thanks for clarifying.