These are the production rules
from
Douglas
R. Hofstadter's book,
Gödel, Escher, Bach: An Eternal Golden Braid
(see pages 259--262 of the 20th anniversary edition).
Using these, is it possible to transform MI to MU?
| 0: | if the string ends in I, append U |
| 1: | if the string starts with M, copy the rest and append it (Mab -> Mabab) |
| 2: | if we have three I's in a row they become a U |
| 3: | two U's in a row are removed |