consider crt being Nat such that
A1:
6700417 < crt
and
A2:
for n being Nat holds
( crt < 2 * ((2 |^ 64) - 1) & crt + ((n * 2) * ((2 |^ 64) - 1)),1 are_congruent_mod ((2 |^ 32) - 1) * 641 & crt + ((n * 2) * ((2 |^ 64) - 1)), - 1 are_congruent_mod 6700417 & crt + ((n * 2) * ((2 |^ 64) - 1)),1 are_congruent_mod 2 )
by Th31;
defpred S1[ Nat] means for n being positive Nat holds (2 |^ n) + $1 is composite ;
set I = { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] } ;
(((2 |^ 32) - 1) * 641) * 6700417 =
((2 |^ 32) - 1) * (641 * 6700417)
.=
((2 |^ 32) - 1) * ((2 |^ 32) + 1)
by Th28
.=
((2 |^ 32) * (2 |^ 32)) - (1 * 1)
.=
(2 |^ (32 + 32)) - 1
by NEWTON:8
;
then
(2 |^ 64) - 1 >= 6700417 * 1
by NAT_1:14, XREAL_1:64;
then
( 2 * ((2 |^ 64) - 1) >= 6700417 * 2 & 6700417 * 2 > 6700417 * 1 )
by XREAL_1:64;
then A3:
2 * ((2 |^ 64) - 1) > 6700417 * 1
by XXREAL_0:2;
( crt + ((0 * 2) * ((2 |^ 64) - 1)),1 are_congruent_mod ((2 |^ 32) - 1) * 641 & crt + ((0 * 2) * ((2 |^ 64) - 1)), - 1 are_congruent_mod 6700417 )
by A2;
then
S1[crt + ((0 * 2) * ((2 |^ 64) - 1))]
by Th35, A1;
then A4:
crt + ((0 * 2) * ((2 |^ 64) - 1)) in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] }
;
then A5:
{ (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] } is non empty natural-membered set
by A4, MEMBERED:def 6;
A6:
for a being Nat st a in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] } holds
ex b being Nat st
( b > a & b in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] } )
proof
let a be
Nat;
( a in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] } implies ex b being Nat st
( b > a & b in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] } ) )
assume
a in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] }
;
ex b being Nat st
( b > a & b in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] } )
then consider k being
Nat such that A7:
(
a = crt + ((k * 2) * ((2 |^ 64) - 1)) &
S1[
crt + ((k * 2) * ((2 |^ 64) - 1))] )
;
A8:
(
crt + (((k + 1) * 2) * ((2 |^ 64) - 1)) = a + (2 * ((2 |^ 64) - 1)) &
a + (2 * ((2 |^ 64) - 1)) > 0 + 6700417 &
a + (2 * ((2 |^ 64) - 1)) > a + 0 )
by A7, A3, XREAL_1:8;
(
crt + (((k + 1) * 2) * ((2 |^ 64) - 1)),1
are_congruent_mod ((2 |^ 32) - 1) * 641 &
crt + (((k + 1) * 2) * ((2 |^ 64) - 1)),
- 1
are_congruent_mod 6700417 )
by A2;
then
S1[
crt + (((k + 1) * 2) * ((2 |^ 64) - 1))]
by A8, Th35;
then
crt + (((k + 1) * 2) * ((2 |^ 64) - 1)) in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] }
;
hence
ex
b being
Nat st
(
b > a &
b in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] } )
by A8;
verum
end;
{ (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] } c= { k where k is Nat : S1[k] }
proof
let x be
object ;
TARSKI:def 3 ( not x in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] } or x in { k where k is Nat : S1[k] } )
assume
x in { (crt + ((k * 2) * ((2 |^ 64) - 1))) where k is Nat : S1[crt + ((k * 2) * ((2 |^ 64) - 1))] }
;
x in { k where k is Nat : S1[k] }
then
ex
k being
Nat st
(
x = crt + ((k * 2) * ((2 |^ 64) - 1)) &
S1[
crt + ((k * 2) * ((2 |^ 64) - 1))] )
;
hence
x in { k where k is Nat : S1[k] }
;
verum
end;
hence
{ k where k is Nat : for n being positive Nat holds (2 |^ n) + k is composite } is infinite
by A6, A5, NUMBER04:1; verum