Here is a derivation of B, C, and I' from the formula in question:

 
   










 

D1.1
D2.1
D1.2
D3.2
D2.4
D4.3
D5.1
D2.9
D2.6
D3.7
D10.10
D3.11
D9.13
D14.14
D15.12
D15.14
D15.16
D17.18

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  1. CCpqCCCsCCsttCqrCpr
  2. CCCpCCpqqCCCCrCCrssCtuCvuwCCvtw

  3. CCCCpqqCCrCCrsstCpt
  4. CCCpCCpqqCCCrstuCCCvCCvwwCCCCxCCxyyCszCrztu
  5. CCCpCCpqqCCCrsstCrt
  6. CCCCCpCCpqqCCCrsstCrtCCuCCuvvww
  7. CCCpCCpqqCCCCrCCrssCtuCvuwCCCCCCvtwxxyy

  8. CCpqCpq                                                                                            [I']
 
9. CCpCCCCqCCqrrCCCsttuCsuvCpv
10. CCpqCpCCqrr
11. CCCpCCpqqCrsCCCCCCtrCtsuuvv
12. CCpqCCCpCCqrrss
13. CpCCCCCCqCprCqrsstt
14. CpCCqCprCqr
15. CCpCCqCCrCqsCrstCpt
16. CCpqCCrCCpCCqsstCrt
17. CCpCqrCqCpr                                                                                    [C]
18. CCpqCCqrCpr
19. CCpqCCrpCrq                                                                                    [B]
       


Dolph Ulrich, 2007