let p1, p2 be Safe Prime; for N being Nat st p1 <> p2 & N = p1 * p2 holds
ex q1, q2 being Sophie_Germain Prime st Euler N = (4 * q1) * q2
let N be Nat; ( p1 <> p2 & N = p1 * p2 implies ex q1, q2 being Sophie_Germain Prime st Euler N = (4 * q1) * q2 )
assume that
A1:
p1 <> p2
and
A2:
N = p1 * p2
; ex q1, q2 being Sophie_Germain Prime st Euler N = (4 * q1) * q2
A3:
p2 > 1
by INT_2:def 4;
consider q2 being Sophie_Germain Prime such that
A4:
Euler p2 = 2 * q2
by Th11;
consider q1 being Sophie_Germain Prime such that
A5:
Euler p1 = 2 * q1
by Th11;
p1 > 1
by INT_2:def 4;
then Euler N =
(Euler p1) * (Euler p2)
by A1, A2, A3, EULER_1:21, INT_2:30
.=
(4 * q1) * q2
by A5, A4
;
hence
ex q1, q2 being Sophie_Germain Prime st Euler N = (4 * q1) * q2
; verum