reserve a,b,c,d,m,x,n,j,k,l for Nat,
  t,u,v,z for Integer,
  f,F for FinSequence of NAT;
reserve p,q,r,s for real number;

theorem
  (t+u) divides ((t+2*u)|^n - u|^n)
  proof
    (t+u) divides ((t+u+u)|^n -u|^n) by Th10;
    hence thesis;
  end;
