theorem
  a,b are_coprime & a + b > 2 & n is even implies not  a+b divides a|^n+b|^n
  proof
    assume
    A1: a,b are_coprime & a + b > 2 & n is even; then
    a+b divides a|^n-b|^n by NEWTON01:36;
    hence thesis by A1,Th31;
  end;
