Mystery Master	Analysis of Surprise Visits	Member

This one-star logic puzzle has 4 noun types, 3 nouns per type, 1 link, 8 facts, 3 rules, but no triggers. It needs only 54 marks, but has 6 grids. Before solving the puzzle, let's take a look at the rules.

Rules

1. Mr. Abbott tried to visit Mr. McNeill.
2. Mr. McNeill tried to visit Peter.
3. The man in Reno tried to visit Reuben.

Let's see if we can violate any of the rules before solving this puzzle. First, you will need to disable the laws.

To violate rule 1, we need to give Mr. Abbott and Mr. McNeill each a home town, but have Mr. Abbott visiting a town that is not Mr. McNeill's home town. So posit Abbott lives in Los Angeles, McNeill in Phoenix, and Abbott visits Reno.

To violate rule 2, let's put Mr. McNeill in Los Angeles, Peter in Phoenix, and have Mr. McNeill visit Reno.

To violate rule 3, let's posit Reuben lives in Phoenix, and the man in Reno visited Los Angeles.

Now that we're done breaking the rules, lets solve this puzzle. Enable the laws, but disable assumptions. The program finds 42/54 marks and 12/18 pairs. All of the facts have been fully examined.

Analysis

Since all of the facts have been fully examined, we'll need to rely on the rules when making assumptions. If we assume that Paul's last name is Abbott, we end up violating rule 1. So Paul's last name must be McNeill. The laws enter the remaining marks, and we have the solution.

With assumptions enabled, the program needs 2 assumptions to find the solution, and to exhaust all possible combinations as well.