User blog comment:KthulhuHimself/Plexation, TaN, and such/@comment-2033667-20151014063209/@comment-27014275-20151014072314

All the members in a string need to be integers. negative numbers aren't integers, and so cannot be members. I could generalize the dimentional skips from a{x}b to a,,,...,b (x commas) but it would take up more space than it needs to, and, tbh, it doesn't make much of a difference.

Thank you for bringing these clarifications to my attention, I'll add them to the blog.

P.S. Can you check the growth speeds? I'm not sure they are precise.