let r be Sequence of REAL ; for y1, y2 being strictly_decreasing Surreal-Sequence
for A being Ordinal st A c= (dom r) /\ (dom y1) & dom y1 = dom y2 & ( for B being Ordinal st B in A holds
y1 .. B == y2 .. B ) holds
Sum ((r | A),((No_omega^ y1) | A)) = Sum ((r | A),((No_omega^ y2) | A))
let y1, y2 be strictly_decreasing Surreal-Sequence; for A being Ordinal st A c= (dom r) /\ (dom y1) & dom y1 = dom y2 & ( for B being Ordinal st B in A holds
y1 .. B == y2 .. B ) holds
Sum ((r | A),((No_omega^ y1) | A)) = Sum ((r | A),((No_omega^ y2) | A))
let O be Ordinal; ( O c= (dom r) /\ (dom y1) & dom y1 = dom y2 & ( for B being Ordinal st B in O holds
y1 .. B == y2 .. B ) implies Sum ((r | O),((No_omega^ y1) | O)) = Sum ((r | O),((No_omega^ y2) | O)) )
assume that
A1:
O c= (dom r) /\ (dom y1)
and
A2:
dom y1 = dom y2
and
A3:
for X being Ordinal st X in O holds
y1 .. X == y2 .. X
; Sum ((r | O),((No_omega^ y1) | O)) = Sum ((r | O),((No_omega^ y2) | O))
set N1 = No_omega^ y1;
set N2 = No_omega^ y2;
defpred S1[ Ordinal] means ( $1 c= O implies Sum ((r | $1),((No_omega^ y1) | $1)) = Sum ((r | $1),((No_omega^ y2) | $1)) );
A4:
( dom (No_omega^ y1) = dom y1 & dom (No_omega^ y2) = dom y2 )
by SURREALC:def 22;
A5:
for B being Ordinal st B in O holds
(No_omega^ y1) .. B == (No_omega^ y2) .. B
proof
let B be
Ordinal;
( B in O implies (No_omega^ y1) .. B == (No_omega^ y2) .. B )
assume A6:
B in O
;
(No_omega^ y1) .. B == (No_omega^ y2) .. B
A7:
B in dom y1
by A1, A6, XBOOLE_0:def 4;
then
(
y1 . B = y1 .. B &
y2 . B = y2 .. B )
by A2, Def5;
then A8:
(
(No_omega^ y1) . B = No_omega^ (y1 .. B) &
(No_omega^ y2) . B = No_omega^ (y2 .. B) )
by A2, A4, A7, SURREALC:def 22;
A9:
y1 .. B == y2 .. B
by A6, A3;
(
(No_omega^ y1) . B = (No_omega^ y1) .. B &
(No_omega^ y2) . B = (No_omega^ y2) .. B )
by A2, A7, A4, Def5;
hence
(No_omega^ y1) .. B == (No_omega^ y2) .. B
by A8, A9, SURREALC:24;
verum
end;
A10:
for A being Ordinal st ( for C being Ordinal st C in A holds
S1[C] ) holds
S1[A]
proof
let A be
Ordinal;
( ( for C being Ordinal st C in A holds
S1[C] ) implies S1[A] )
assume A11:
for
C being
Ordinal st
C in A holds
S1[
C]
;
S1[A]
assume A12:
A c= O
;
Sum ((r | A),((No_omega^ y1) | A)) = Sum ((r | A),((No_omega^ y2) | A))
then A13:
A c= (dom r) /\ (dom y1)
by A1;
reconsider X1 =
[ { ((Sum ((r | B),((No_omega^ y1) | B))) + ((uReal . ((r . B) - e)) * ((No_omega^ y1) .. B))) where B is Element of A, e is positive Real : B in A } , { ((Sum ((r | B),((No_omega^ y1) | B))) + ((uReal . ((r . B) + e)) * ((No_omega^ y1) .. B))) where B is Element of A, e is positive Real : B in A } ] as
Surreal by A13, A4, Th61;
reconsider X2 =
[ { ((Sum ((r | B),((No_omega^ y2) | B))) + ((uReal . ((r . B) - e)) * ((No_omega^ y2) .. B))) where B is Element of A, e is positive Real : B in A } , { ((Sum ((r | B),((No_omega^ y2) | B))) + ((uReal . ((r . B) + e)) * ((No_omega^ y2) .. B))) where B is Element of A, e is positive Real : B in A } ] as
Surreal by A13, A2, A4, Th61;
A14:
L_ X1 <==> L_ X2
proof
thus
L_ X1 <=_ L_ X2
SURREALO:def 4 L_ X2 <=_ L_ X1proof
let x be
Surreal;
SURREALO:def 3 ( not x in L_ X1 or ex b1, b2 being set st
( b1 in L_ X2 & b2 in L_ X2 & b1 <= x & x <= b2 ) )
assume
x in L_ X1
;
ex b1, b2 being set st
( b1 in L_ X2 & b2 in L_ X2 & b1 <= x & x <= b2 )
then consider B being
Element of
A,
e being
positive Real such that A15:
(
x = (Sum ((r | B),((No_omega^ y1) | B))) + ((uReal . ((r . B) - e)) * ((No_omega^ y1) .. B)) &
B in A )
;
B c= O
by A12, A15, ORDINAL1:10;
then A16:
Sum (
(r | B),
((No_omega^ y1) | B))
= Sum (
(r | B),
((No_omega^ y2) | B))
by A11, A15;
(uReal . ((r . B) - e)) * ((No_omega^ y1) .. B) == (uReal . ((r . B) - e)) * ((No_omega^ y2) .. B)
by A12, A15, A5, SURREALR:54;
then
(
x == (Sum ((r | B),((No_omega^ y2) | B))) + ((uReal . ((r . B) - e)) * ((No_omega^ y2) .. B)) &
(Sum ((r | B),((No_omega^ y2) | B))) + ((uReal . ((r . B) - e)) * ((No_omega^ y2) .. B)) in L_ X2 )
by A15, A16, SURREALR:66;
hence
ex
b1,
b2 being
set st
(
b1 in L_ X2 &
b2 in L_ X2 &
b1 <= x &
x <= b2 )
;
verum
end;
let x be
Surreal;
SURREALO:def 3 ( not x in L_ X2 or ex b1, b2 being set st
( b1 in L_ X1 & b2 in L_ X1 & b1 <= x & x <= b2 ) )
assume
x in L_ X2
;
ex b1, b2 being set st
( b1 in L_ X1 & b2 in L_ X1 & b1 <= x & x <= b2 )
then consider B being
Element of
A,
e being
positive Real such that A17:
(
x = (Sum ((r | B),((No_omega^ y2) | B))) + ((uReal . ((r . B) - e)) * ((No_omega^ y2) .. B)) &
B in A )
;
B c= O
by A12, A17, ORDINAL1:10;
then A18:
Sum (
(r | B),
((No_omega^ y1) | B))
= Sum (
(r | B),
((No_omega^ y2) | B))
by A11, A17;
(uReal . ((r . B) - e)) * ((No_omega^ y1) .. B) == (uReal . ((r . B) - e)) * ((No_omega^ y2) .. B)
by A12, A17, A5, SURREALR:54;
then
(
x == (Sum ((r | B),((No_omega^ y1) | B))) + ((uReal . ((r . B) - e)) * ((No_omega^ y1) .. B)) &
(Sum ((r | B),((No_omega^ y1) | B))) + ((uReal . ((r . B) - e)) * ((No_omega^ y1) .. B)) in L_ X1 )
by A17, A18, SURREALR:66;
hence
ex
b1,
b2 being
set st
(
b1 in L_ X1 &
b2 in L_ X1 &
b1 <= x &
x <= b2 )
;
verum
end;
A19:
R_ X1 <==> R_ X2
proof
thus
R_ X1 <=_ R_ X2
SURREALO:def 4 R_ X2 <=_ R_ X1proof
let x be
Surreal;
SURREALO:def 3 ( not x in R_ X1 or ex b1, b2 being set st
( b1 in R_ X2 & b2 in R_ X2 & b1 <= x & x <= b2 ) )
assume
x in R_ X1
;
ex b1, b2 being set st
( b1 in R_ X2 & b2 in R_ X2 & b1 <= x & x <= b2 )
then consider B being
Element of
A,
e being
positive Real such that A20:
(
x = (Sum ((r | B),((No_omega^ y1) | B))) + ((uReal . ((r . B) + e)) * ((No_omega^ y1) .. B)) &
B in A )
;
B c= O
by A12, A20, ORDINAL1:10;
then A21:
Sum (
(r | B),
((No_omega^ y1) | B))
= Sum (
(r | B),
((No_omega^ y2) | B))
by A11, A20;
(uReal . ((r . B) + e)) * ((No_omega^ y1) .. B) == (uReal . ((r . B) + e)) * ((No_omega^ y2) .. B)
by A12, A20, A5, SURREALR:54;
then
(
x == (Sum ((r | B),((No_omega^ y2) | B))) + ((uReal . ((r . B) + e)) * ((No_omega^ y2) .. B)) &
(Sum ((r | B),((No_omega^ y2) | B))) + ((uReal . ((r . B) + e)) * ((No_omega^ y2) .. B)) in R_ X2 )
by A20, A21, SURREALR:66;
hence
ex
b1,
b2 being
set st
(
b1 in R_ X2 &
b2 in R_ X2 &
b1 <= x &
x <= b2 )
;
verum
end;
let x be
Surreal;
SURREALO:def 3 ( not x in R_ X2 or ex b1, b2 being set st
( b1 in R_ X1 & b2 in R_ X1 & b1 <= x & x <= b2 ) )
assume
x in R_ X2
;
ex b1, b2 being set st
( b1 in R_ X1 & b2 in R_ X1 & b1 <= x & x <= b2 )
then consider B being
Element of
A,
e being
positive Real such that A22:
(
x = (Sum ((r | B),((No_omega^ y2) | B))) + ((uReal . ((r . B) + e)) * ((No_omega^ y2) .. B)) &
B in A )
;
B c= O
by A12, A22, ORDINAL1:10;
then A23:
Sum (
(r | B),
((No_omega^ y1) | B))
= Sum (
(r | B),
((No_omega^ y2) | B))
by A11, A22;
(uReal . ((r . B) + e)) * ((No_omega^ y1) .. B) == (uReal . ((r . B) + e)) * ((No_omega^ y2) .. B)
by A12, A22, A5, SURREALR:54;
then
(
x == (Sum ((r | B),((No_omega^ y1) | B))) + ((uReal . ((r . B) + e)) * ((No_omega^ y1) .. B)) &
(Sum ((r | B),((No_omega^ y1) | B))) + ((uReal . ((r . B) + e)) * ((No_omega^ y1) .. B)) in R_ X1 )
by A22, A23, SURREALR:66;
hence
ex
b1,
b2 being
set st
(
b1 in R_ X1 &
b2 in R_ X1 &
b1 <= x &
x <= b2 )
;
verum
end;
A24:
X1 == X2
by A14, A19, SURREALO:29;
A25:
(
Sum (
(r | A),
((No_omega^ y1) | A))
= Unique_No X1 &
Unique_No X1 == X1 )
by Th62, A13, A4, SURREALO:def 10;
A26:
(
Sum (
(r | A),
((No_omega^ y2) | A))
= Unique_No X2 &
Unique_No X2 == X2 )
by A2, Th62, A13, A4, SURREALO:def 10;
X2 == Sum (
(r | A),
((No_omega^ y1) | A))
by A24, A25, SURREALO:4;
then
Sum (
(r | A),
((No_omega^ y2) | A))
== Sum (
(r | A),
((No_omega^ y1) | A))
by A26, SURREALO:4;
hence
Sum (
(r | A),
((No_omega^ y1) | A))
= Sum (
(r | A),
((No_omega^ y2) | A))
by SURREALO:50;
verum
end;
for A being Ordinal holds S1[A]
from ORDINAL1:sch 2(A10);
hence
Sum ((r | O),((No_omega^ y1) | O)) = Sum ((r | O),((No_omega^ y2) | O))
; verum