set P = 6n+1_Primes ;
assume A1:
6n+1_Primes is finite
; contradiction
set N = 6 * (Product (Sgm 6n+1_Primes));
A2:
Sgm 6n+1_Primes is positive-yielding
then A4:
6 * (Product (Sgm 6n+1_Primes)) >= 6 * 1
by Th2, XREAL_1:64;
then reconsider M = (((6 * (Product (Sgm 6n+1_Primes))) ^2) - (6 * (Product (Sgm 6n+1_Primes)))) + 1 as Element of NAT by INT_1:3;
(((6 * (Product (Sgm 6n+1_Primes))) ^2) - (6 * (Product (Sgm 6n+1_Primes)))) + 1 >= 1 + 1
by A5, XREAL_1:6;
then consider p being Element of NAT such that
A6:
p is prime
and
A7:
p divides M
by INT_2:31;
reconsider p = p as Prime by A6;
A8:
((6 * (Product (Sgm 6n+1_Primes))) * (6 * (Product (Sgm 6n+1_Primes)))) * (6 * (Product (Sgm 6n+1_Primes))) = (6 * (Product (Sgm 6n+1_Primes))) |^ 3
by POLYEQ_5:2;
A9:
((6 * (Product (Sgm 6n+1_Primes))) |^ 3) * ((6 * (Product (Sgm 6n+1_Primes))) |^ 3) = (6 * (Product (Sgm 6n+1_Primes))) |^ (3 + 3)
by NEWTON:8;
A10:
p > 1
by INT_2:def 4;
then A13:
6 * (Product (Sgm 6n+1_Primes)),p are_coprime
by Th4;
then A14:
((6 * (Product (Sgm 6n+1_Primes))) |^ (order ((6 * (Product (Sgm 6n+1_Primes))),p))) mod p = 1
by A10, PEPIN:def 2;
A15:
(- 1) mod p = p - 1
by Th5;
A16:
p -' 1 = p - 1
by XREAL_0:def 2;
(((6 * (Product (Sgm 6n+1_Primes))) ^2) - (6 * (Product (Sgm 6n+1_Primes)))) + 1 divides ((((6 * (Product (Sgm 6n+1_Primes))) ^2) - (6 * (Product (Sgm 6n+1_Primes)))) + 1) * ((6 * (Product (Sgm 6n+1_Primes))) + 1)
;
then
p divides ((((6 * (Product (Sgm 6n+1_Primes))) ^2) - (6 * (Product (Sgm 6n+1_Primes)))) + 1) * ((6 * (Product (Sgm 6n+1_Primes))) + 1)
by A7, INT_2:9;
then
p divides ((6 * (Product (Sgm 6n+1_Primes))) |^ 3) - (- 1)
by A8;
then A17:
(6 * (Product (Sgm 6n+1_Primes))) |^ 3, - 1 are_congruent_mod p
;
then A18: ((6 * (Product (Sgm 6n+1_Primes))) |^ 3) mod p =
(- 1) mod p
by NAT_D:64
.=
p - 1
by Th5
;
A19:
1 mod p = 1
by INT_2:def 4, NAT_D:24;
A22:
now ( not p = 2 & not p = 3 )end;
((6 * (Product (Sgm 6n+1_Primes))) |^ 3) * ((6 * (Product (Sgm 6n+1_Primes))) |^ 3),(- 1) * (- 1) are_congruent_mod p
by A17, INT_1:18;
then
((6 * (Product (Sgm 6n+1_Primes))) |^ 6) mod p = 1
by A9, INT_2:def 4, NAT_6:12;
then
order ((6 * (Product (Sgm 6n+1_Primes))),p) divides 6
by A10, A11, Th4, PEPIN:47;