let A be decreasing Ordinal-Sequence; for B being non-empty natural-valued Ordinal-Sequence st dom A = dom B holds
ex C being Cantor-normal-form Ordinal-Sequence st
( omega -exponent C = A & omega -leading_coeff C = B )
let B be non-empty natural-valued Ordinal-Sequence; ( dom A = dom B implies ex C being Cantor-normal-form Ordinal-Sequence st
( omega -exponent C = A & omega -leading_coeff C = B ) )
assume A1:
dom A = dom B
; ex C being Cantor-normal-form Ordinal-Sequence st
( omega -exponent C = A & omega -leading_coeff C = B )
deffunc H1( Ordinal) -> set = (B . $1) *^ (exp (omega,(A . $1)));
consider C being Ordinal-Sequence such that
A2:
( dom C = dom A & ( for a being Ordinal st a in dom A holds
C . a = H1(a) ) )
from ORDINAL2:sch 3();
now for a, b being Ordinal st a in b & b in dom C holds
omega -exponent (C . b) in omega -exponent (C . a)let a,
b be
Ordinal;
( a in b & b in dom C implies omega -exponent (C . b) in omega -exponent (C . a) )assume A6:
(
a in b &
b in dom C )
;
omega -exponent (C . b) in omega -exponent (C . a)then A7:
(
C . a = (B . a) *^ (exp (omega,(A . a))) &
C . b = (B . b) *^ (exp (omega,(A . b))) )
by A2, ORDINAL1:10;
XA:
rng B c= NAT
by VALUED_0:def 6;
X0:
b in dom B
by A6, A1, A2;
then
b c= dom B
by ORDINAL1:def 2;
then xy:
(
B . b in rng B &
B . a in rng B )
by A6, X0, FUNCT_1:3;
(
B . a <> {} &
B . b <> {} )
by A1, A2, A6, ORDINAL1:10, FUNCT_1:def 9;
then
(
0 c< B . a &
0 c< B . b )
by XBOOLE_1:2, XBOOLE_0:def 8;
then
(
0 in B . a &
0 in B . b )
by ORDINAL1:11;
then
(
omega -exponent (C . b) = A . b &
omega -exponent (C . a) = A . a )
by A7, ORDINAL5:58, XA, xy;
hence
omega -exponent (C . b) in omega -exponent (C . a)
by A2, A6, ORDINAL5:def 1;
verum end;
then reconsider C = C as Cantor-normal-form Ordinal-Sequence by A3, ORDINAL5:def 11;
take
C
; ( omega -exponent C = A & omega -leading_coeff C = B )
A9:
dom (omega -exponent C) = dom A
by A2, Def1;
now for a being object st a in dom (omega -exponent C) holds
(omega -exponent C) . a = A . alet a be
object ;
( a in dom (omega -exponent C) implies (omega -exponent C) . a = A . a )assume
a in dom (omega -exponent C)
;
(omega -exponent C) . a = A . athen A10:
a in dom C
by Def1;
then A11:
C . a = (B . a) *^ (exp (omega,(A . a)))
by A2;
B . a <> {}
by A1, A2, A10, FUNCT_1:def 9;
then
0 c< B . a
by XBOOLE_1:2, XBOOLE_0:def 8;
then A12:
0 in B . a
by ORDINAL1:11;
Sa:
B . a in rng B
by FUNCT_1:3, A10, A1, A2;
rng B c= NAT
by VALUED_0:def 6;
then
omega -exponent (C . a) = A . a
by A11, A12, ORDINAL5:58, Sa;
hence
(omega -exponent C) . a = A . a
by A10, Def1;
verum end;
hence
omega -exponent C = A
by A9, FUNCT_1:2; omega -leading_coeff C = B
A13:
dom (omega -leading_coeff C) = dom B
by A1, A2, Def3;
hence
omega -leading_coeff C = B
by A13, FUNCT_1:2; verum