您可以使用

log(P1+P2+...+Pn) = log(P1[1 + P2/P1 + ... + Pn/P1]) 
                  = log(P1) + log(1 + P2/P1 + ... + Pn/P1])

适用于任何Pi.因此，排除maxP = max_i Pi会导致

which works for any Pi. So factoring out maxP = max_i Pi results in

log(P1+P2+...+Pn) = log(maxP) + log(1+P2/maxP + ... + Pn/maxP)

所有比率均小于1的地方.

where all the ratios are less than 1.