 reserve n,i,k,m for Nat;
 reserve p for Prime;

theorem SetPrime1:
  SetPrimes 0 = {} & SetPrimes 1 = {}
  proof
    0+1 is not Prime by INT_2:def 4; then
    SetPrimes (0+1) = SetPrimes 0 by PrimesSet;
    hence thesis;
  end;
