let n, m be Nat; ( 2 * m <= n implies ex CardF being XFinSequence of st
( card (Domin_0 n,m) = (Sum CardF) + (card (Domin_0 (n -' 1),m)) & dom CardF = m & ( for j being Nat st j < m holds
CardF . j = (card (Domin_0 (2 * j),j)) * (card (Domin_0 (n -' (2 * (j + 1))),(m -' (j + 1)))) ) ) )
assume A1:
2 * m <= n
; ex CardF being XFinSequence of st
( card (Domin_0 n,m) = (Sum CardF) + (card (Domin_0 (n -' 1),m)) & dom CardF = m & ( for j being Nat st j < m holds
CardF . j = (card (Domin_0 (2 * j),j)) * (card (Domin_0 (n -' (2 * (j + 1))),(m -' (j + 1)))) ) )
set Z = Domin_0 n,m;
set Zne = { pN where pN is Element of NAT ^omega : ( pN in Domin_0 n,m & { N where N is Element of NAT : ( 2 * (Sum (pN | N)) = N & N > 0 ) } <> {} ) } ;
A2:
{ pN where pN is Element of NAT ^omega : ( pN in Domin_0 n,m & { N where N is Element of NAT : ( 2 * (Sum (pN | N)) = N & N > 0 ) } <> {} ) } c= Domin_0 n,m
set Ze = { pN where pN is Element of NAT ^omega : ( pN in Domin_0 n,m & { N where N is Element of NAT : ( 2 * (Sum (pN | N)) = N & N > 0 ) } = {} ) } ;
A3:
{ pN where pN is Element of NAT ^omega : ( pN in Domin_0 n,m & { N where N is Element of NAT : ( 2 * (Sum (pN | N)) = N & N > 0 ) } = {} ) } c= Domin_0 n,m
reconsider Zne = { pN where pN is Element of NAT ^omega : ( pN in Domin_0 n,m & { N where N is Element of NAT : ( 2 * (Sum (pN | N)) = N & N > 0 ) } <> {} ) } as finite set by A2;
consider C being XFinSequence of such that
A4:
card Zne = Sum C
and
A5:
dom C = m
and
A6:
for j being Nat st j < m holds
C . j = (card (Domin_0 (2 * j),j)) * (card (Domin_0 (n -' (2 * (j + 1))),(m -' (j + 1))))
by A1, Th41;
reconsider Ze = { pN where pN is Element of NAT ^omega : ( pN in Domin_0 n,m & { N where N is Element of NAT : ( 2 * (Sum (pN | N)) = N & N > 0 ) } = {} ) } as finite set by A3;
take
C
; ( card (Domin_0 n,m) = (Sum C) + (card (Domin_0 (n -' 1),m)) & dom C = m & ( for j being Nat st j < m holds
C . j = (card (Domin_0 (2 * j),j)) * (card (Domin_0 (n -' (2 * (j + 1))),(m -' (j + 1)))) ) )
A7:
Ze misses Zne
A11:
Domin_0 n,m c= Ze \/ Zne
Ze \/ Zne c= Domin_0 n,m
by A3, A2, XBOOLE_1:8;
then A14:
Ze \/ Zne = Domin_0 n,m
by A11, XBOOLE_0:def 10;
hence
( card (Domin_0 n,m) = (Sum C) + (card (Domin_0 (n -' 1),m)) & dom C = m & ( for j being Nat st j < m holds
C . j = (card (Domin_0 (2 * j),j)) * (card (Domin_0 (n -' (2 * (j + 1))),(m -' (j + 1)))) ) )
by A5, A6; verum