public class Floats {
  private static void expect(boolean v) {
    if (! v) throw new RuntimeException();
  }

  private static double multiply(double a, double b) {
    return a * b;
  }

  private static float multiply(float a, float b) {
    return a * b;
  }

  private static double divide(double a, double b) {
    return a / b;
  }

  private static double subtract(double a, double b) {
    return a - b;
  }

  public static void main(String[] args) {
    expect(multiply(0.5d, 0.5d) == 0.25d);
    expect(multiply(0.5f, 0.5f) == 0.25f);

    expect(multiply(0.5d, 0.5d) < 0.5d);
    expect(multiply(0.5f, 0.5f) < 0.5f);

    expect(multiply(0.5d, 0.5d) > 0.1d);
    expect(multiply(0.5f, 0.5f) > 0.1f);

    expect(divide(0.5d, 0.5d) == 1.0d);

    expect(subtract(0.5d, 0.5d) == 0.0d);
  }
}