let r1, r2 be Real; (sReal . r1) * (sReal . r2) == sReal . (r1 * r2)
set r12 = r1 * r2;
set R1 = sReal . r1;
set R2 = sReal . r2;
set R12 = sReal . (r1 * r2);
A1:
(sReal . r1) * (sReal . r2) = [((comp ((L_ (sReal . r1)),(sReal . r1),(sReal . r2),(L_ (sReal . r2)))) \/ (comp ((R_ (sReal . r1)),(sReal . r1),(sReal . r2),(R_ (sReal . r2))))),((comp ((L_ (sReal . r1)),(sReal . r1),(sReal . r2),(R_ (sReal . r2)))) \/ (comp ((R_ (sReal . r1)),(sReal . r1),(sReal . r2),(L_ (sReal . r2)))))]
by SURREALR:50;
A2:
comp ((L_ (sReal . r1)),(sReal . r1),(sReal . r2),(L_ (sReal . r2))) << {(sReal . (r1 * r2))}
proof
let a,
b be
Surreal;
SURREAL0:def 20 ( not a in comp ((L_ (sReal . r1)),(sReal . r1),(sReal . r2),(L_ (sReal . r2))) or not b in {(sReal . (r1 * r2))} or not b <= a )
assume A3:
(
a in comp (
(L_ (sReal . r1)),
(sReal . r1),
(sReal . r2),
(L_ (sReal . r2))) &
b in {(sReal . (r1 * r2))} )
;
not b <= a
consider x1,
y1 being
Surreal such that A4:
(
a = ((x1 * (sReal . r2)) + ((sReal . r1) * y1)) - (x1 * y1) &
x1 in L_ (sReal . r1) &
y1 in L_ (sReal . r2) )
by A3, SURREALR:def 15;
consider n1 being
Nat such that A5:
x1 = uDyadic . ([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1))
by Th42, A4;
set d1 =
[/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1);
consider n2 being
Nat such that A6:
y1 = uDyadic . ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2))
by Th42, A4;
set d2 =
[/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2);
A7:
a == sReal . (((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (r1 * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2))))
by A4, A5, A6, Lm18;
(
0 < r1 - ([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) &
0 < r2 - ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)) )
by Th41, XREAL_1:50;
then
0 < (r1 - ([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1))) * (r2 - ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))
;
then
0 < (r1 * r2) - (((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)) * r1)) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2))))
;
then consider k being
Nat such that A8:
((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)) * r1)) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2))) < [/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)
by Th54, XREAL_1:47;
set d =
[/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k);
(
sReal . (((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (r1 * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) < sReal . ([/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)) &
sReal . ([/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)) == uDyadic . ([/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)) )
by A8, Th50, Th46;
then
(
sReal . (((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (r1 * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) <= uDyadic . ([/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)) &
uDyadic . ([/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)) < sReal . (r1 * r2) )
by Th44, SURREALO:4;
then
(
sReal . (((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (r1 * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) < sReal . (r1 * r2) &
sReal . (r1 * r2) = b )
by SURREALO:4, A3, TARSKI:def 1;
hence
not
b <= a
by A7, SURREALO:4;
verum
end;
comp ((R_ (sReal . r1)),(sReal . r1),(sReal . r2),(R_ (sReal . r2))) << {(sReal . (r1 * r2))}
proof
let a,
b be
Surreal;
SURREAL0:def 20 ( not a in comp ((R_ (sReal . r1)),(sReal . r1),(sReal . r2),(R_ (sReal . r2))) or not b in {(sReal . (r1 * r2))} or not b <= a )
assume A9:
(
a in comp (
(R_ (sReal . r1)),
(sReal . r1),
(sReal . r2),
(R_ (sReal . r2))) &
b in {(sReal . (r1 * r2))} )
;
not b <= a
consider x1,
y1 being
Surreal such that A10:
(
a = ((x1 * (sReal . r2)) + ((sReal . r1) * y1)) - (x1 * y1) &
x1 in R_ (sReal . r1) &
y1 in R_ (sReal . r2) )
by A9, SURREALR:def 15;
consider n1 being
Nat such that A11:
x1 = uDyadic . ([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1))
by Th43, A10;
set d1 =
[\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1);
consider n2 being
Nat such that A12:
y1 = uDyadic . ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2))
by Th43, A10;
set d2 =
[\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2);
A13:
a == sReal . (((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (r1 * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2))))
by A10, A11, A12, Lm18;
(
r1 - ([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) < 0 &
r2 - ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)) < 0 )
by Th41, XREAL_1:49;
then
0 < (r1 - ([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1))) * (r2 - ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))
;
then
0 < (r1 * r2) - (((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)) * r1)) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2))))
;
then consider k being
Nat such that A14:
((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)) * r1)) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2))) < [/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)
by Th54, XREAL_1:47;
set d =
[/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k);
(
sReal . (((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (r1 * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) < sReal . ([/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)) &
sReal . ([/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)) == uDyadic . ([/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)) )
by A14, Th50, Th46;
then
(
sReal . (((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (r1 * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) <= uDyadic . ([/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)) &
uDyadic . ([/(((r1 * r2) * (2 |^ k)) - 1)\] / (2 |^ k)) < sReal . (r1 * r2) )
by Th44, SURREALO:4;
then
(
sReal . (((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (r1 * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) < sReal . (r1 * r2) &
sReal . (r1 * r2) = b )
by SURREALO:4, A9, TARSKI:def 1;
hence
not
b <= a
by A13, SURREALO:4;
verum
end;
then A15:
L_ ((sReal . r1) * (sReal . r2)) << {(sReal . (r1 * r2))}
by A1, A2, SURREAL0:41;
A16:
{(sReal . (r1 * r2))} << comp ((L_ (sReal . r1)),(sReal . r1),(sReal . r2),(R_ (sReal . r2)))
proof
let b,
a be
Surreal;
SURREAL0:def 20 ( not b in {(sReal . (r1 * r2))} or not a in comp ((L_ (sReal . r1)),(sReal . r1),(sReal . r2),(R_ (sReal . r2))) or not a <= b )
assume A17:
(
b in {(sReal . (r1 * r2))} &
a in comp (
(L_ (sReal . r1)),
(sReal . r1),
(sReal . r2),
(R_ (sReal . r2))) )
;
not a <= b
consider x1,
y1 being
Surreal such that A18:
(
a = ((x1 * (sReal . r2)) + ((sReal . r1) * y1)) - (x1 * y1) &
x1 in L_ (sReal . r1) &
y1 in R_ (sReal . r2) )
by A17, SURREALR:def 15;
consider n1 being
Nat such that A19:
x1 = uDyadic . ([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1))
by Th42, A18;
set d1 =
[/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1);
consider n2 being
Nat such that A20:
y1 = uDyadic . ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2))
by Th43, A18;
set d2 =
[\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2);
A21:
a == sReal . (((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (r1 * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2))))
by A18, A19, A20, Lm18;
(
0 < r1 - ([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) &
r2 - ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)) < 0 )
by Th41, XREAL_1:49, XREAL_1:50;
then
(r1 - ([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1))) * (r2 - ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2))) < 0
;
then
(r1 * r2) - (((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)) * r1)) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) < 0
;
then consider k being
Nat such that A22:
[\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k) < ((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)) * r1)) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))
by Th53, XREAL_1:48;
set d =
[\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k);
(
uDyadic . ([\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k)) == sReal . ([\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k)) &
sReal . ([\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k)) < sReal . (((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (r1 * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) )
by A22, Th50, Th46;
then
(
sReal . (r1 * r2) < uDyadic . ([\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k)) &
uDyadic . ([\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k)) <= sReal . (((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (r1 * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) )
by Th44, SURREALO:4;
then
(
b = sReal . (r1 * r2) &
sReal . (r1 * r2) < sReal . (((([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * r2) + (r1 * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) - (([/((r1 * (2 |^ n1)) - 1)\] / (2 |^ n1)) * ([\((r2 * (2 |^ n2)) + 1)/] / (2 |^ n2)))) )
by SURREALO:4, A17, TARSKI:def 1;
hence
not
a <= b
by A21, SURREALO:4;
verum
end;
{(sReal . (r1 * r2))} << comp ((R_ (sReal . r1)),(sReal . r1),(sReal . r2),(L_ (sReal . r2)))
proof
let b,
a be
Surreal;
SURREAL0:def 20 ( not b in {(sReal . (r1 * r2))} or not a in comp ((R_ (sReal . r1)),(sReal . r1),(sReal . r2),(L_ (sReal . r2))) or not a <= b )
assume A23:
(
b in {(sReal . (r1 * r2))} &
a in comp (
(R_ (sReal . r1)),
(sReal . r1),
(sReal . r2),
(L_ (sReal . r2))) )
;
not a <= b
consider x1,
y1 being
Surreal such that A24:
(
a = ((x1 * (sReal . r2)) + ((sReal . r1) * y1)) - (x1 * y1) &
x1 in R_ (sReal . r1) &
y1 in L_ (sReal . r2) )
by A23, SURREALR:def 15;
consider n1 being
Nat such that A25:
x1 = uDyadic . ([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1))
by Th43, A24;
set d1 =
[\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1);
consider n2 being
Nat such that A26:
y1 = uDyadic . ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2))
by Th42, A24;
set d2 =
[/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2);
A27:
a == sReal . (((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (r1 * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2))))
by A24, A25, A26, Lm18;
(
0 < r2 - ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)) &
r1 - ([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) < 0 )
by Th41, XREAL_1:49, XREAL_1:50;
then
(r1 - ([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1))) * (r2 - ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2))) < 0
;
then
(r1 * r2) - (((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)) * r1)) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) < 0
;
then consider k being
Nat such that A28:
[\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k) < ((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)) * r1)) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))
by Th53, XREAL_1:48;
set d =
[\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k);
(
uDyadic . ([\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k)) == sReal . ([\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k)) &
sReal . ([\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k)) < sReal . (((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (r1 * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) )
by A28, Th50, Th46;
then
(
sReal . (r1 * r2) < uDyadic . ([\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k)) &
uDyadic . ([\(((r1 * r2) * (2 |^ k)) + 1)/] / (2 |^ k)) <= sReal . (((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (r1 * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) )
by Th44, SURREALO:4;
then
(
b = sReal . (r1 * r2) &
sReal . (r1 * r2) < sReal . (((([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * r2) + (r1 * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) - (([\((r1 * (2 |^ n1)) + 1)/] / (2 |^ n1)) * ([/((r2 * (2 |^ n2)) - 1)\] / (2 |^ n2)))) )
by SURREALO:4, A23, TARSKI:def 1;
hence
not
a <= b
by A27, SURREALO:4;
verum
end;
then A29:
{(sReal . (r1 * r2))} << R_ ((sReal . r1) * (sReal . r2))
by A1, A16, SURREAL0:42;
A30:
L_ (sReal . (r1 * r2)) << {((sReal . r1) * (sReal . r2))}
proof
let a,
b be
Surreal;
SURREAL0:def 20 ( not a in L_ (sReal . (r1 * r2)) or not b in {((sReal . r1) * (sReal . r2))} or not b <= a )
assume A31:
(
a in L_ (sReal . (r1 * r2)) &
b in {((sReal . r1) * (sReal . r2))} )
;
not b <= a
consider n being
Nat such that A32:
a = uDyadic . ([/(((r1 * r2) * (2 |^ n)) - 1)\] / (2 |^ n))
by Th42, A31;
set d =
[/(((r1 * r2) * (2 |^ n)) - 1)\] / (2 |^ n);
0 < (r1 * r2) - ([/(((r1 * r2) * (2 |^ n)) - 1)\] / (2 |^ n))
by Th41, XREAL_1:50;
then consider k being
Nat such that A33:
1
/ (2 |^ k) <= (r1 * r2) - ([/(((r1 * r2) * (2 |^ n)) - 1)\] / (2 |^ n))
by PREPOWER:92;
set M = 1
/ (2 |^ k);
consider k1 being
Nat such that A34:
r1 - (1 / (2 |^ k)) < [/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)
by Th54, XREAL_1:44;
set d1 =
[/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1);
consider k2 being
Nat such that A35:
r2 - (1 / (2 |^ k)) < [/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)
by Th54, XREAL_1:44;
set d2 =
[/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2);
(
0 < r1 - ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) &
r1 - ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) < 1
/ (2 |^ k) &
0 < r2 - ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)) &
r2 - ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)) < 1
/ (2 |^ k) )
by Th41, A34, A35, XREAL_1:11, XREAL_1:50;
then
(
0 < (r1 - ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (r2 - ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))) &
(r1 - ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (r2 - ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))) < (1 / (2 |^ k)) * (1 / (2 |^ k)) )
by XREAL_1:96;
then
(r1 * r2) - (((r1 * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)))) < (1 / (2 |^ k)) * (1 / (2 |^ k))
;
then A36:
(r1 * r2) - ((1 / (2 |^ k)) * (1 / (2 |^ k))) < ((r1 * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)))
by XREAL_1:11;
1
<= 1
* (2 |^ k)
by NAT_1:14;
then
1
/ (2 |^ k) <= 1
by XREAL_1:79;
then A37:
(1 / (2 |^ k)) * (1 / (2 |^ k)) <= (1 / (2 |^ k)) * 1
by XREAL_1:64;
(
[/(((r1 * r2) * (2 |^ n)) - 1)\] / (2 |^ n) <= (r1 * r2) - (1 / (2 |^ k)) &
(r1 * r2) - (1 / (2 |^ k)) <= (r1 * r2) - ((1 / (2 |^ k)) * (1 / (2 |^ k))) )
by A33, A37, XREAL_1:10, XREAL_1:11;
then
[/(((r1 * r2) * (2 |^ n)) - 1)\] / (2 |^ n) <= (r1 * r2) - ((1 / (2 |^ k)) * (1 / (2 |^ k)))
by XXREAL_0:2;
then
[/(((r1 * r2) * (2 |^ n)) - 1)\] / (2 |^ n) < ((r1 * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)))
by A36, XXREAL_0:2;
then
(
a == sReal . ([/(((r1 * r2) * (2 |^ n)) - 1)\] / (2 |^ n)) &
sReal . ([/(((r1 * r2) * (2 |^ n)) - 1)\] / (2 |^ n)) < sReal . (((r1 * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)))) )
by A32, Th50, Th46;
then A38:
a <= sReal . (((r1 * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))))
by SURREALO:4;
A39:
(
L_ ((sReal . r1) * (sReal . r2)) << {((sReal . r1) * (sReal . r2))} &
(sReal . r1) * (sReal . r2) in {((sReal . r1) * (sReal . r2))} )
by TARSKI:def 1, SURREALO:11;
(
uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) in L_ (sReal . r1) &
uDyadic . ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)) in L_ (sReal . r2) )
by Th42;
then
(((sReal . r1) * (uDyadic . ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)))) + ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (sReal . r2))) - ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (uDyadic . ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)))) in comp (
(L_ (sReal . r1)),
(sReal . r1),
(sReal . r2),
(L_ (sReal . r2)))
by SURREALR:def 15;
then A40:
(((sReal . r1) * (uDyadic . ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)))) + ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (sReal . r2))) + (- ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (uDyadic . ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))))) in L_ ((sReal . r1) * (sReal . r2))
by XBOOLE_0:def 3, A1;
(((sReal . r1) * (uDyadic . ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)))) + ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (sReal . r2))) + (- ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (uDyadic . ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))))) == sReal . (((r1 * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))))
by Lm18;
then
sReal . (((r1 * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([/((r2 * (2 |^ k2)) - 1)\] / (2 |^ k2)))) < (sReal . r1) * (sReal . r2)
by A40, A39, SURREALO:4;
then
a < (sReal . r1) * (sReal . r2)
by A38, SURREALO:4;
hence
not
b <= a
by A31, TARSKI:def 1;
verum
end;
{((sReal . r1) * (sReal . r2))} << R_ (sReal . (r1 * r2))
proof
let b,
a be
Surreal;
SURREAL0:def 20 ( not b in {((sReal . r1) * (sReal . r2))} or not a in R_ (sReal . (r1 * r2)) or not a <= b )
assume A41:
(
b in {((sReal . r1) * (sReal . r2))} &
a in R_ (sReal . (r1 * r2)) )
;
not a <= b
consider n being
Nat such that A42:
a = uDyadic . ([\(((r1 * r2) * (2 |^ n)) + 1)/] / (2 |^ n))
by Th43, A41;
set d =
[\(((r1 * r2) * (2 |^ n)) + 1)/] / (2 |^ n);
0 < ([\(((r1 * r2) * (2 |^ n)) + 1)/] / (2 |^ n)) - (r1 * r2)
by Th41, XREAL_1:50;
then consider k being
Nat such that A43:
1
/ (2 |^ k) <= ([\(((r1 * r2) * (2 |^ n)) + 1)/] / (2 |^ n)) - (r1 * r2)
by PREPOWER:92;
set M = 1
/ (2 |^ k);
consider k1 being
Nat such that A44:
r1 - (1 / (2 |^ k)) < [/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)
by Th54, XREAL_1:44;
set d1 =
[/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1);
consider k2 being
Nat such that A45:
[\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2) < r2 + (1 / (2 |^ k))
by Th53, XREAL_1:29;
set d2 =
[\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2);
(
0 < r1 - ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) &
r1 - ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) < 1
/ (2 |^ k) &
0 < ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)) - r2 &
([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)) - r2 < 1
/ (2 |^ k) )
by Th41, A44, A45, XREAL_1:11, XREAL_1:19, XREAL_1:50;
then
(
0 < (r1 - ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)) - r2) &
(r1 - ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)) - r2) < (1 / (2 |^ k)) * (1 / (2 |^ k)) )
by XREAL_1:96;
then
(((r1 * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)))) - (r1 * r2) < (1 / (2 |^ k)) * (1 / (2 |^ k))
;
then A46:
((r1 * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))) < ((1 / (2 |^ k)) * (1 / (2 |^ k))) + (r1 * r2)
by XREAL_1:19;
1
<= 1
* (2 |^ k)
by NAT_1:14;
then
1
/ (2 |^ k) <= 1
by XREAL_1:79;
then A47:
(1 / (2 |^ k)) * (1 / (2 |^ k)) <= (1 / (2 |^ k)) * 1
by XREAL_1:64;
(
[\(((r1 * r2) * (2 |^ n)) + 1)/] / (2 |^ n) >= (r1 * r2) + (1 / (2 |^ k)) &
(r1 * r2) + (1 / (2 |^ k)) >= (r1 * r2) + ((1 / (2 |^ k)) * (1 / (2 |^ k))) )
by A43, A47, XREAL_1:6, XREAL_1:19;
then
[\(((r1 * r2) * (2 |^ n)) + 1)/] / (2 |^ n) >= (r1 * r2) + ((1 / (2 |^ k)) * (1 / (2 |^ k)))
by XXREAL_0:2;
then
[\(((r1 * r2) * (2 |^ n)) + 1)/] / (2 |^ n) > ((r1 * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)))
by A46, XXREAL_0:2;
then
(
sReal . (((r1 * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)))) < sReal . ([\(((r1 * r2) * (2 |^ n)) + 1)/] / (2 |^ n)) &
sReal . ([\(((r1 * r2) * (2 |^ n)) + 1)/] / (2 |^ n)) == a )
by A42, Th50, Th46;
then A48:
sReal . (((r1 * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)))) <= a
by SURREALO:4;
A49:
(
{((sReal . r1) * (sReal . r2))} << R_ ((sReal . r1) * (sReal . r2)) &
(sReal . r1) * (sReal . r2) in {((sReal . r1) * (sReal . r2))} )
by TARSKI:def 1, SURREALO:11;
(
uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) in L_ (sReal . r1) &
uDyadic . ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)) in R_ (sReal . r2) )
by Th42, Th43;
then
(((sReal . r1) * (uDyadic . ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)))) + ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (sReal . r2))) - ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (uDyadic . ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)))) in comp (
(L_ (sReal . r1)),
(sReal . r1),
(sReal . r2),
(R_ (sReal . r2)))
by SURREALR:def 15;
then A50:
(((sReal . r1) * (uDyadic . ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)))) + ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (sReal . r2))) + (- ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (uDyadic . ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))))) in R_ ((sReal . r1) * (sReal . r2))
by XBOOLE_0:def 3, A1;
(((sReal . r1) * (uDyadic . ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2)))) + ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (sReal . r2))) + (- ((uDyadic . ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1))) * (uDyadic . ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))))) == sReal . (((r1 * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))))
by Lm18;
then
(sReal . r1) * (sReal . r2) < sReal . (((r1 * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))) + (r2 * ([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)))) - (([/((r1 * (2 |^ k1)) - 1)\] / (2 |^ k1)) * ([\((r2 * (2 |^ k2)) + 1)/] / (2 |^ k2))))
by A50, A49, SURREALO:4;
then
(sReal . r1) * (sReal . r2) < a
by A48, SURREALO:4;
hence
not
a <= b
by A41, TARSKI:def 1;
verum
end;
hence
(sReal . r1) * (sReal . r2) == sReal . (r1 * r2)
by A15, A29, A30, SURREAL0:43; verum