CSI 2165, Winter 2006

Assignment 1

Due Monday, Feb 6, 11am

Submission instructions: The submission is done electronically through Virtual Campus.

Please submit a file called a1.pl with comments inside. The first comment should include your name and student number. The file should contain the Prolog code for the required predicates, and comments explaining what they do and how they do it. Add in comments example queries that you ran for testing each predicate and what the Prolog output was (thorough testing is important). Make sure your program can be loaded (consulted) in Prolog without giving errors. Make sure the name of the file and the names of the predicates are the required ones.

Note: No late assignments are allowed.

The Prolog application that you are going to implement is about solving the following murder mystery:

jean was killed on tuesday; the only suspects are:

luc, paul, alain, bernard, and louis.

The rules to follow are:

• The murderer is somebody who has a motive to kill jean, who owns a gun, and who does not have an alibi for Tuesday.

• An alibi provided by a person who is not trustworthy is not accepted.

• Somebody has a motive to kill jean if he has a special interest in killing jean or he wants revenge.

• Somebody has a special interest in killing jean is he is the beneficiary of jean’s fortune, or if he owns money to jean, or if jean surprised him committing a crime.

Here are the facts established by the investigation:

luc has an alibi for tuesday given by bernard

paul has an alibi for tuesday given by bernard

louis has an alibi for tuesday given by luc

alain has an alibi for thursday given by luc

alain is not a trustworthy person

paul wants to take revenge on jean

luc wants to take revenge on jean

bernard is the beneficiary of jean’s fortune

jean is the beneficiary of louis’s fortune

louis owns money to jean

luc owns money to jean

jean has seen alain committing a crime

luc owns a gun

louis owns a gun

alain owns a gun

1. Implement the above facts and rules for describing the problem.

(You choose the names of these predicates.)

2. Have Prolog solve the murder mystery, by using the facts and the rules to answer the question:

who killed jean?

The predicate that solves the mistery should be called solve, with one argument (solve/1), the name of the murderer. This predicate passes the necessary arguments to your predicates from part 1. (namely the victim, jean and the day, tuesday).

Have fun!!!