Here's a derivation of HI-2 from HI-8 in eighteen steps:

 
 



 
          1. CCpqCCCrCspCqtCpt                                      [HI-8]
D1.1   =  2. CCCpCqCrsCCCCtCurCsvCrvwCCrsw
D2.2   =  3. CCpqCpq
D2.3   =  4. CCpqCrCpq
D1.4   =  5. CCCpCqCrsCCtCrsuCCrsu
D4.1   =  6. CpCCqrCCCsCtqCruCqu
D4.2   =  7. CpCCCqCrCstCCCCuCvsCtwCswxCCstx
D1.6   =  8. CCCpCqrCCCstCCCuCvsCtwCswxCrx
D4.5   =  9. CpCCCqCrCstCCuCstvCCstv
D5.7   = 10. CCCCCpCqrCstCrtuCCrsu
D8.3   = 11. CpCqp                                                                [Simp]
D5.9   = 12. CCCpCqrsCCqrs
D1.11  = 13. CCCpCqrCCsrtCrt
D10.12 = 14. CCpqCCqrCpr                                                   [Syl]
D14.13 = 15. CCCpqrCCCsCtpCCupqr
D14.14 = 16. CCCCpqCrqsCCrps
D16.10 = 17. CCpCCqCrsCtuCCstCpCsu
D17.17 = 18. CCpqCCCrpCqsCps
D11.18 = 19. CpCCqrCCCsqCrtCqt                                  [HI-2]
 
 
Dolph Ulrich, 2007