set D = the carrier of R;
consider g being Function of [:NAT ,the carrier of R:],the carrier of R such that
A1:
for a being Element of the carrier of R holds
( g . 0 ,a = 0. R & ( for n being Element of NAT holds g . (n + 1),a = the addF of R . a,(g . n,a) ) )
from BINOM:sch 1();
take
g
; for a being Element of R holds
( g . 0 ,a = 0. R & ( for n being Element of NAT holds g . (n + 1),a = a + (g . n,a) ) )
thus
for a being Element of R holds
( g . 0 ,a = 0. R & ( for n being Element of NAT holds g . (n + 1),a = a + (g . n,a) ) )
by A1; verum