code: static public Probability and(Probability probability1, Probability probability2) {
          double p1 = probability1.value;
          double p2 = probability2.value;
          return new Probability(p1 * p2);
      }
docs: This function returns the logical conjunction of the specified probabilities.  The value
  of the logical conjunction of two probabilities is P * Q.
  
  @param probability1 The first probability.
  @param probability2 The second probability.
  @return The logical conjunction of the two probabilities.