let r1, r2 be Real; ( sReal . r1 < sReal . r2 iff r1 < r2 )
set R1 = sReal . r1;
set R2 = sReal . r2;
A1:
( L_ (sReal . r1) << {(sReal . r1)} & {(sReal . r1)} << R_ (sReal . r1) & sReal . r1 in {(sReal . r1)} & L_ (sReal . r2) << {(sReal . r2)} & {(sReal . r2)} << R_ (sReal . r2) & sReal . r2 in {(sReal . r2)} )
by SURREALO:11, TARSKI:def 1;
thus
( sReal . r1 < sReal . r2 implies r1 < r2 )
( r1 < r2 implies sReal . r1 < sReal . r2 )proof
assume A2:
sReal . r1 < sReal . r2
;
r1 < r2
then A3:
r1 <> r2
by SURREALO:3;
assume
not
r1 < r2
;
contradiction
then
r2 < r1
by A3, XXREAL_0:1;
then
0 < r1 - r2
by XREAL_1:50;
then consider k being
Nat such that A4:
1
/ (2 |^ k) <= r1 - r2
by PREPOWER:92;
set K2 = 2
|^ (k + 1);
2
|^ (k + 1) = 2
* (2 |^ k)
by NEWTON:6;
then A5:
(2 |^ (k + 1)) * (1 / (2 |^ k)) =
2
* ((2 |^ k) * (1 / (2 |^ k)))
.=
2
* 1
by XCMPLX_1:106
;
A6:
(2 |^ (k + 1)) * (r2 + (1 / (2 |^ k))) <= r1 * (2 |^ (k + 1))
by A4, XREAL_1:19, XREAL_1:64;
A7:
uDyadic . ([/((r1 * (2 |^ (k + 1))) - 1)\] / (2 |^ (k + 1))) <= sReal . r1
by A1, Th42;
sReal . r2 <= uDyadic . ([\((r2 * (2 |^ (k + 1))) + 1)/] / (2 |^ (k + 1)))
by A1, Th43;
then
sReal . r1 < uDyadic . ([\((r2 * (2 |^ (k + 1))) + 1)/] / (2 |^ (k + 1)))
by A2, SURREALO:4;
then
uDyadic . ([/((r1 * (2 |^ (k + 1))) - 1)\] / (2 |^ (k + 1))) < uDyadic . ([\((r2 * (2 |^ (k + 1))) + 1)/] / (2 |^ (k + 1)))
by A7, SURREALO:4;
then
(
(r1 * (2 |^ (k + 1))) - 1
<= [/((r1 * (2 |^ (k + 1))) - 1)\] &
[/((r1 * (2 |^ (k + 1))) - 1)\] < [\((r2 * (2 |^ (k + 1))) + 1)/] )
by Th24, XREAL_1:72, INT_1:def 7;
then
(
(r1 * (2 |^ (k + 1))) - 1
< [\((r2 * (2 |^ (k + 1))) + 1)/] &
[\((r2 * (2 |^ (k + 1))) + 1)/] <= (r2 * (2 |^ (k + 1))) + 1 )
by XXREAL_0:2, INT_1:def 6;
then
(r1 * (2 |^ (k + 1))) - 1
< (r2 * (2 |^ (k + 1))) + 1
by XXREAL_0:2;
then
(
((r1 * (2 |^ (k + 1))) - 1) + 1
< ((r2 * (2 |^ (k + 1))) + 1) + 1 &
((r2 * (2 |^ (k + 1))) + 1) + 1
= (r2 * (2 |^ (k + 1))) + 2 )
by XREAL_1:6;
hence
contradiction
by A6, A5;
verum
end;
assume
r1 < r2
; sReal . r1 < sReal . r2
then
0 < r2 - r1
by XREAL_1:50;
then consider k being Nat such that
A8:
1 / (2 |^ k) <= r2 - r1
by PREPOWER:92;
set K2 = 2 |^ (k + 1);
2 |^ (k + 1) = 2 * (2 |^ k)
by NEWTON:6;
then A9: (2 |^ (k + 1)) * (1 / (2 |^ k)) =
2 * ((2 |^ k) * (1 / (2 |^ k)))
.=
2 * 1
by XCMPLX_1:106
;
(2 |^ (k + 1)) * (r1 + (1 / (2 |^ k))) <= r2 * (2 |^ (k + 1))
by A8, XREAL_1:19, XREAL_1:64;
then
(((2 |^ (k + 1)) * r1) + 2) - 1 <= (r2 * (2 |^ (k + 1))) - 1
by A9, XREAL_1:9;
then
( [\(((2 |^ (k + 1)) * r1) + 1)/] <= ((2 |^ (k + 1)) * r1) + 1 & ((2 |^ (k + 1)) * r1) + 1 <= (r2 * (2 |^ (k + 1))) - 1 )
by INT_1:def 6;
then
( [\(((2 |^ (k + 1)) * r1) + 1)/] <= (r2 * (2 |^ (k + 1))) - 1 & (r2 * (2 |^ (k + 1))) - 1 <= [/((r2 * (2 |^ (k + 1))) - 1)\] )
by XXREAL_0:2, INT_1:def 7;
then
[\(((2 |^ (k + 1)) * r1) + 1)/] <= [/((r2 * (2 |^ (k + 1))) - 1)\]
by XXREAL_0:2;
then A10:
uDyadic . ([\(((2 |^ (k + 1)) * r1) + 1)/] / (2 |^ (k + 1))) <= uDyadic . ([/((r2 * (2 |^ (k + 1))) - 1)\] / (2 |^ (k + 1)))
by XREAL_1:72, Th24;
sReal . r1 < uDyadic . ([\(((2 |^ (k + 1)) * r1) + 1)/] / (2 |^ (k + 1)))
by A1, Th43;
then A11:
sReal . r1 < uDyadic . ([/((r2 * (2 |^ (k + 1))) - 1)\] / (2 |^ (k + 1)))
by A10, SURREALO:4;
uDyadic . ([/((r2 * (2 |^ (k + 1))) - 1)\] / (2 |^ (k + 1))) <= sReal . r2
by A1, Th42;
hence
sReal . r1 < sReal . r2
by A11, SURREALO:4; verum