reserve E,F,G for RealNormSpace;
reserve f for Function of E,F;
reserve g for Function of F,G;
reserve a,b,c for Point of E;
reserve t for Real;

theorem Th9:
  lim (NAT --> a) = a
  proof
    thus lim (NAT --> a) = (NAT --> a).0 by NDIFF_1:18
    .= a;
  end;
