The following misprints have been kindly pointed out to the author, mostly by Dr Max Halperin. On page 637, line 1 and page 638, line 6, - €a0 should be - JaJThe equals sign of (2-5) should be read as for small px. The last line of page 637 should be p11-p1-21−n1/p12+n2/1−p12n1+n2b12−1b12