let x, y be Surreal; ( not x == 0_No & not x + y == 0_No & omega-y x = omega-y (x + y) & omega-r x = omega-r (x + y) implies |.y.| infinitely< |.x.| )
set r = omega-r x;
set w = omega-y x;
set N = No_omega^ (omega-y x);
set R = uReal . (omega-r x);
assume that
A1:
( not x == 0_No & not x + y == 0_No )
and
A2:
( omega-y x = omega-y (x + y) & omega-r x = omega-r (x + y) )
; |.y.| infinitely< |.x.|
let s be positive Real; SURREALC:def 3 |.y.| * (uReal . s) < |.x.|
A3:
( |.x.|, No_omega^ (omega-y x) are_commensurate & |.(x + y).|, No_omega^ (omega-y x) are_commensurate )
by A1, A2, Def7;
A4:
0_No <= uReal . s
by SURREALI:def 8;
A5:
|.(x - ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))).| infinitely< |.x.|
by A1, Def8;
|.((x + y) - ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))).| infinitely< |.(x + y).|
by A1, A2, Def8;
then A6:
|.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| infinitely< |.x.|
by Th16, A3, Th4;
((No_omega^ (omega-y x)) * (uReal . (omega-r x))) - ((No_omega^ (omega-y x)) * (uReal . (omega-r x))) == 0_No
by SURREALR:39;
then A7:
( (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))) + (((No_omega^ (omega-y x)) * (uReal . (omega-r x))) + (- x)) = ((- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))) + ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))) + (- x) & ((- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))) + ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))) + (- x) == 0_No + (- x) & 0_No + (- x) = - x )
by SURREALR:43, SURREALR:37;
A8:
x - x == 0_No
by SURREALR:39;
(x + y) + (- x) = y + (x + (- x))
by SURREALR:37;
then A9:
( (x + y) + (- x) == y + 0_No & y + 0_No = y )
by A8, SURREALR:43;
- (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))) = (No_omega^ (omega-y x)) * (uReal . (omega-r x))
;
then
- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))) = ((No_omega^ (omega-y x)) * (uReal . (omega-r x))) + (- x)
by SURREALR:40;
then
( ((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))) + (- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))) = (x + y) + ((- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))) + (((No_omega^ (omega-y x)) * (uReal . (omega-r x))) + (- x))) & (x + y) + ((- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))) + (((No_omega^ (omega-y x)) * (uReal . (omega-r x))) + (- x))) == (x + y) + (- x) )
by A7, SURREALR:43, SURREALR:37;
then
((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))) + (- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))) == y
by A9, SURREALO:4;
then
( |.y.| == |.(((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))) + (- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))))).| & |.(((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))) + (- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))))).| <= |.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| + |.(- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))).| )
by Th48, Th37;
then
|.y.| <= |.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| + |.(- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))).|
by SURREALO:4;
then
( |.y.| * (uReal . s) <= (|.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| + |.(- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))).|) * (uReal . s) & (|.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| + |.(- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))).|) * (uReal . s) == (|.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| * (uReal . s)) + (|.(- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))).| * (uReal . s)) )
by A4, SURREALR:67, SURREALR:75;
then A10:
|.y.| * (uReal . s) <= (|.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| * (uReal . s)) + (|.(- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))).| * (uReal . s))
by SURREALO:4;
A11:
|.x.| = |.x.| * (uReal . 1)
by SURREALN:48;
|.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| * (uReal . (s * 2)) < |.x.|
by A6;
then A12:
|.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| * (uReal . ((s * 2) * (1 / 2))) <= |.x.| * (uReal . (1 * (1 / 2)))
by Th59, A11;
|.(x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| * (uReal . (s * 2)) < |.x.|
by A5;
then A13:
|.(x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| * (uReal . ((s * 2) * (1 / 2))) < |.x.| * (uReal . (1 * (1 / 2)))
by Th59, A11;
|.(x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| * (uReal . s) == |.(- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))).| * (uReal . s)
by SURREALR:51, Th40;
then
|.(- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))).| * (uReal . ((s * 2) * (1 / 2))) < |.x.| * (uReal . (1 * (1 / 2)))
by A13, SURREALO:4;
then A14:
(|.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| * (uReal . s)) + (|.(- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))).| * (uReal . s)) < (|.x.| * (uReal . (1 * (1 / 2)))) + (|.x.| * (uReal . (1 * (1 / 2))))
by A12, SURREALR:44;
( (|.x.| * (uReal . (1 * (1 / 2)))) + (|.x.| * (uReal . (1 * (1 / 2)))) == |.x.| * ((uReal . (1 / 2)) + (uReal . (1 / 2))) & |.x.| * ((uReal . (1 / 2)) + (uReal . (1 / 2))) == |.x.| * (uReal . ((1 / 2) + (1 / 2))) )
by SURREALR:67, SURREALR:51, SURREALN:55;
then
( (|.x.| * (uReal . (1 * (1 / 2)))) + (|.x.| * (uReal . (1 * (1 / 2)))) == |.x.| * (uReal . 1) & |.x.| * (uReal . 1) = |.x.| )
by SURREALN:48, SURREALO:4;
then
(|.((x + y) + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x))))).| * (uReal . s)) + (|.(- (x + (- ((No_omega^ (omega-y x)) * (uReal . (omega-r x)))))).| * (uReal . s)) < |.x.|
by A14, SURREALO:4;
hence
|.y.| * (uReal . s) < |.x.|
by A10, SURREALO:4; verum