. (26) alt Let us take the discrete version of (26) as r e.Fi = xt +F(re)— Ivi + ifs, replace with r e = log we and expouentiate to obtain wi+i = e(los wilAtwt, (27) where Ae . Since F(x) —t 0 for large we, we recover a pure multiplicative model wt+1 = Atwe for the tail. The condition that F(x) becomes ve