reserve X,Y,z,s for set, L,L1,L2,A,B for List of X, x for Element of X,
  O,O1,O2,O3 for Operation of X, a,b,y for Element of X, n,m for Nat;
reserve F,F1,F2 for filtering Operation of X;
reserve i for Element of NAT;
reserve X for ConstructorDB, A for FinSequence of the Constrs of X,
  x for Element of X;
reserve Y for ref-finite ConstructorDB,
  B for FinSequence of the Constrs of Y,
  y for Element of Y;

theorem
  ATLEAST(A) c= ATLEAST-(A,n)
  proof
    ATLEAST(A) = ATLEAST-(A,0) & 0 <= n by Th67,NAT_1:2;
    hence thesis by Th70;
  end;
