theorem Th40:
  5 divides 2|^(4*n+2) + 1
  proof
A1: 2|^2+1 divides 2|^2|^(2*n+1) + 1|^(2*n+1) by NEWTON01:35;
    2|^2|^(2*n+1) = 2|^(2*(2*n+1)) by NEWTON:9;
    hence thesis by A1,Lm1;
  end;
