1'A.ll JEAB PLANA 



[4] 



X, 1 ( X, X, -f- *, X k ) 2 . a x b*c*d* = 



— rX, { 



-^x^x/^xyx^- 



-hX^X.^'Xr^-'X^- 



-t-X^Xs+'XS-'Xs*- 



xjx, x+ *x 3 >-xs- 



■4-X i >X, % + >X/-'XS- 



+X t *X x+ *X 3 *-'Xf- 



+ XfX x +*X % *—X£- 



X^-'XsXf—Xf 



-*.x x -'Xsx 3 *->xj 

 +x s *->x 3 *xs-x t * 



-*-X % x -\XsX ; ?-'X i * 



X % x Xs +s X 3 i:+, XS +, \ 

 + X i x X,» + 3 XS +t X i ^'l 

 +X 3 x X,o +i X s * + 'XJ+'i 



-hX, x X/ + , X^ + , X,» +l ) 



xjx, x+i \y +i x.y 

 -¥-X s *X x+i X^ +, X 3 ^'l 

 +X s >X x+i X s * +, X % ' i+t l 

 ■+-XSX, x+i X % * +, Xf + ') 



—rx; 



X m *X, i **X, t —X t v —) 



■X^XS + 'X^-'X'-' 



^-x 3 *x^**x 3 *-'X x -' 



■X^X,^'X^-'X^-' 



xsx,*+*x 3 x -xs- 



•X**X,f+*X t x —Xf— 



■ X^XS+'X^-XS- 

 •X t *X t t+'X*-X t >- 



X^-'XSX.t-XS 



■xs-xjx 3 *-*x x 



•Xi'-'XfXJ—XS 

 • Xs-XfXt-Xf 



XsX^XJ+'X^' 



■ X i *X*+ 3 X i * +, X 3 x+l 



■ X t 'X,' l+i X s * +l X % x+ ' 

 XsX,* +i XS + 'X 5 x +' 

 XJW+'XS+'Xf*' 



■X^X^X^'X^*' 



■ X 3 i X,t +i X i x+t X^ + ' 

 ■X^X,* +i X % x+ 'X 3 ^'j 



En nous rescrvant de determiner dans chaquc cas particulicr les detu 

 Bommes donnees par les termes multiplies par — r V,', il est facile tie 

 voir , que Ton a oclle fornmlc ; Sffvoir 



