cof.I A cof.iB (cof ID4- cof i D'-i + cof ^ (A+B')) 

 + co( iC cof - D (cnf i A'+ cof ^ B - i+cof I (A+B/) 

 - cof 1 A cof ^ B (cof MC -f- D) cof -; (C - D)) 

 4- cof -; (A + B)' + cof l (A + B) cof i (C - D) 

 + cof ; (A -4- B) cof l (C -f- D) 



— cof -; A cof -; B (cof -; (C + D) -h cof ; (A + B)) 



(cof ; (C - D) -f- cof ; ( A + B)) 

 rr4Cof;Acof;B(cq(A+B+C+D)cf^(A+B-C-D) 

 cofi(A+B+C-D)cof;(A+B-C+D). 



Tum vero fimili ratione oftenditiir fore pro pofleriorL 

 fa<ftore 



Q (cof ; E' H- fm. ; (A - B)') = cof ; A cof | B 



(cof ; D^- H- cof i C^ - I + cof ; (A - B')) 

 +-cofiCcof;D(cof;A'+cof;B -i + cof;(A-B)') 

 = cof.;Acof;B(cof;(D+C)cU(D-C)+cof;(A-B)i 

 H- cof ; (A - B) cof ; (D - C) 

 -+- cof ; (A - B) cof ; (D + C) 

 rz cof ; A cof ; B (cof ; (C + D) + cof ; (A - B)) 

 (cof ; (C - D) -H cof ; ( A - B)) 



= 4Cof4A cof jBcof;(A-B+C+D)cfl(B+C+D-A) 

 cof ;(A-B+C-D) cof i(A-B-C+D). 



Hincque colIe(flim fumcndo obtinetur: 



-Q^(cof;E^-fin.;(A+B)0(cof;E'-fin.;(A-B)') 



^•cofKA + B + C-D^cofKA + B-C + D)^ 



"' "-'^ ^^ lcof-:(A+B + C + l-Ocofi(A + B-C-D)f 

 tcof;(A-B + C-D}cofKA-B-C + D)j 

 :r:+^ i6cof ; A'cof ;B\N% 



N 2 Tndc 



