example 122 B

123456789
  1. RL
  2. AAA = (BBB, CCC)
  3. BBB = (DDD, EEE)
  4. CCC = (ZZZ, GGG)
  5. DDD = (DDD, DDD)
  6. EEE = (EEE, EEE)
  7. GGG = (GGG, GGG)
  8. ZZZ = (ZZZ, ZZZ)