The formula CCCCppqrCCsCrtCqCs is easily provable in BCI*:

 
                       1. CCpqCCrpCrq                                                           [B]
                 2. CCpCqrCqCpr                                                          [C]
                 3. CCppCqq                                                                      [I*]
D1.1  =   4. CCpCqrCpCCsqCsr
D2.1
 =   5. CCpqCCqrCpr
D2.3 =   6. CpCCqqp
D4.2 =   7. CCpCqrCCsqCsCpr
D5.6 =   8. CCCCppqrCqr
D7.7
 =   9. CCpCqrCpCCsCrtCqCst
D9.8 = 10. CCCCppqrCCsCrtCqCst                                     [The axiom]
 
 
It, in turn, delivers B, C, and I*.  My original derivation of the latter three from it runs 34 lines long (though I note that Larry Wos has since used OTTER to find a shorter (29-line) proof). 
 
 










 

D1.1
D2.1
D2.3
D1.4
D5.3
D6.1
D2.7
D1.8
D2.9
D9.10
D11.11
D8.11 D12.12 D13.14
D1.14 D14.15 D16.13 D1.18 D19.17 D2.20 D21.21 D13.22 D23.23 D23.1 D1.24 D25.24 D26.27 D25.28 D14.29 D30.25 D31.31 D15.32 D14.33

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  1. CCCCppqrCCsCrtCqCst                              [The axiom]
   2. CCpCCCqCrsCCttCqsuCrCpu
   3. CpCCCCqqrCssCrCCtCpuCtu
   4. CpCqCCpCrrCCsCqtCst
   5. CCpCCqCCCCrrsCttCCuCqvCuvwCsCpw
   6. CCCCppqCrrCsCqCCtCsuCtu
   7. CpCCqqCCrCpsCrs
   8. CCppCqCCrCqsCrs
  
9. CCpCCqCCrCqsCrstCCuuCpt
 
10. CCppCCqCCrCCsCrtCstuCqu
 
11.
CCppCCqqCCrCstCsCrt

 12.
CCppCCqCrsCrCqs
 13. CpCCqCprCqr
 
14. CCpCqrCqCpr                                                    
[Com]
 
15. CCpCCCqCrsCrCqstCpt
 
16. CCpCCqCCrrstCCqsCpt
 
17. CpCCpCCCqCrsCrCqstt
 
18. CCpqCCrrCpq
 
19. CCpCCCqqCCrrstCsCpt
 
20. CpCCqqp
 
21. CCppCqq                                                                
[I*]
 
22. Cpp
 
23. CCpCCqqrCpr
 
24. CCCppCCqqrr
 
25. CCCCppqrCqCCrss
 
26. CCpCqrCCCssqCpr
 
27. CCCppqCCqrr
 
28. CCCppCqrCCCssqr
 
29. CCpqCCCCCrrpqss
 
30. CCCCCppqrsCCqrs
 
31. CCpqCpCCqrr
 
32. CCpqCCCpCCqrrss
 
33. CCpqCCqrCpr
 
34. CCpqCCrpCrq                                                    
[B]
   
 
Dolph Ulrich, 2007