the following questions about uncertainty representation and reasoning in production systems using the MYCIN's certainty factor system: (i) If condition 1 is satisfied with certainty 0.8 and condition 2 is satisfied with certainty 0.9, what is the certainty with which condition 1 AND condition 2 will be satisfied? (ii) If a conclusion can be drawn from Rule 1 with certainty 0.8 and the same conclusion can also be drawn from Rule 2 with certainty 0.9, what is the certainty with which this conclusion can be drawn by using both Rule 1 and Rule 2