
theorem Th11:
  for p be Safe Prime ex q be Sophie_Germain Prime st Euler p = 2*q
proof
  let p be Safe Prime;
A1: Euler p = p-1 by EULER_1:20;
  ex q be Sophie_Germain Prime st p = 2*q+1 by Th10;
  hence thesis by A1;
end;
