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;
reserve a,b,c,d,m,x,n,k,l for Nat,
  t,z for Integer,
  f,F,G for FinSequence of REAL;
reserve q,r,s for real number;
reserve D for set;

theorem Th85:
  not 5 divides a|^2 - 2 & not 5 divides a|^2 + 2 &
    not 5 divides a|^2 - 3 & not 5 divides a|^2 + 3
  proof
    5 = 2*2 + 1;
    hence thesis by Th84,PEPIN:59;
  end;
