CORRECTIOX. 



Page 307, line 15 should read 

 (Ai^ix,', X.,', . . . x,/^y/, yJ, . . . yj) = {Al^x^, z., . . . x^ly^,y^, . . . y„), 

 instead of 



{A^Xi',X.^', . . . Xj) = (A^Xi,X.2, . . . x„). 



