• Troubleshooting
• Prolog
• Dataset
• Getting Started
• Warmup
• Parents
• More Rules
• Numbers in Prolog
• Extra Credit (10 pts)
• Lab Questions
• Submission

This lab requires an independent study of the Java language. You are encouraged to use any web tutorials and resources to learn Prolog beyond those in the book and provided by me (i.e. you will need to find them).

• I will not debug your code -> But I will help you get your program running if you have exhausted all other resources.
• I do not look at code or programs sent to me over email -> But I am willing to work with you during my office hours or during an appointment to clarify and point you in the right direction.
• I am more than willing to discuss your grade or significant issues you are having with the assignments -> But only during my office hours or during an appointment and not during class time when the focus is on other things.
• I am not your IT person nor do I have the expertise to claim I am, therefore I probably can't help get the software running on your system -> But if you visit during my office hours or an appointment I probably can point you in the right direction.

For this lab, you will use Prolog. You can install it on Windows, Mac, and Linux by downloading from here: http://www.swi-prolog.org/download/stable.

Once you have Prolog installed on your machine, clone this repository and start the lab. Good Luck!

Begin by taking a look at the file royal.pl in the project directory. This data was adapted from http://ftp.aset.psu.edu/~saw/royal/. This file is a set of Prolog facts that represents the genealogy of the royal House of Windsor.

Next, create a new file prolog_lab.pl. This file should be in the same directory as royal.pl. In this file, you will include all your Prolog rules you will be asked to write in the lab.

Your program should begin with your name as a comment.

 % First_name Last_name
 % CSCI 305 Prolog Lab 2

Check that everything is working. First load the royal.pl file:

 ?- consult(royal)

Next, load the file you created above in SWI-Prolog. Now, run the query:

 ?- parent(X, 'Queen Elizabeth II').

The symbol ?- is the Prolog query prompt. You do not need to retype this. This query asks who is the parent of Queen Elizabeth II. Prolog first returns the result X = 'King George VI'. Type a semicolon (;). This will prompt Prolog for the next result. Prolog then returns X = 'Lady Elizabeth Bowes-Lyon'. The period following the second result indicates there are no additional results.

The entire query and result interaction should appear as:

 ?- parent(X, 'Queen Elizabeth II').
 X = 'King George VI' ;
 X = 'Lady Elizabeth Bowes-Lyon'.

Replicate this exchange on your own machine.

In this lab you will create a number of Prolog rules that define a number of common familial relationships.

In Prolog parlance, we define a rule as its name and its arity. For instance the rule mother/2 indicates a rule named mother with two arguments.

 mother(M,C):- parent(M,C), female(M).

Add this rule to your Prolog file. Reload your file. Test your new rule with the query:

 ?- mother(X, 'Queen Elizabeth II').

which should return the single result:

 X = 'Lady Elizabeth Bowes-Lynon'.

Now write the rule father/2 and add it to your file.

Now write a set of additional rules. In your rules, you are encouraged to make use of other rules you have written. This may effect the order you choose to implement these rules.

Make sure you get the order of the arguments correct as switching then will change the meaning of the function.

• spouse/2
• child/2
• son/2
• daughter/2
• sibling/2
• brother/2
• sister/2
• uncle/2 (two rules: one by blood, one by marriage.)
• aunt/2 (two rules: one by blood, one by marriage.)
• grandparent/2
• grandfather/2
• grandmother/2
• grandchild/2

For the next two rules, make use of rules you have already written. It may take more than one rule to define these functions. You may find tracing useful. To debug, you can use the keyword trace to enable tracing and notrace to disable.

Write the rules:

• ancestor/2 (ancestor(X, Y) means X is the ancestor of Y)
• descendant/2 (descendant(X, Y) means X is the descendant of Y)

Now we will write some Prolog rules that require numeric comparisons. Write the rules:

• older/2
• younger/2

The rule older(X, Y) indicates person X is older than person Y. The rule younger/2 should be written in a similar manner.

Lastly, write the rule regentWhenBorn/2. This rule, regentWhenBorn(X, Y), should ask who was King or Queen (X) when person Y was born.

Write rule(x) that define the first cousin relationship, cousin/2. You should look up the formal definition of cousin. You do not need to support second or third cousins, nor cousins removed.

EC1. What is the result of query:

 ?- cousin(X, 'Prince Charles').

EC2. What is the result of query:

 ?- cousin('Prince Charles', X).

For these lab questions, you are expected to use Prolog to answer. Answers that are given without providing the Prolog rules that derive it will receive no credit. Some queries have multiple answers and you are expected to provide all results to the lab questions. Use the semicolon (;) to prompt Prolog for additional results. However, you may omit duplicate results, if the same name appears more than once in your result set.

1. What is the result of query: ?- father(X, 'Queen Elizabeth II').?
2. What is the result of query: ?- grandmother(X, 'Queen Elizabeth II').?
3. What is the result of query: ?- grandfather(X, 'Queen Elizabeth II').?
4. What is the result of query: ?- grandparent(X, 'Queen Elizabeth II').?
5. What is the result of query: ?- grandparent('Queen Elizabeth II', X).?
6. What is the result of query: ?- sibling(X, 'Queen Elizabeth II').?
7. What is the result of query: ?- son(X, 'Queen Elizabeth II').?
8. What is the result of query: ?- daughter(X, 'Queen Elizabeth II').?
9. What is the result of query: ?- aunt(X, 'Lady Diana Spencer').?
10. What is the result of query: ?- spouse(X, 'Prince William').?
11. What is the result of query: ?- ancestor(X, 'Prince Henry').?
12. What is the result of query: ?- descendant('Queen Victoria', Y).?
13. What is the result of query: ?- older('Prince Henry', 'Prince William').?
14. What is the result of query: ?- older(X, 'Queen Elizabeth II').?
15. What is the result of query: ?- regentWhenBorn(X, 'Queen Elizabeth II').?

The following questions are for feedback and evaluation purposes. Points are awarded for any sincere answer.

16. Name something you like about Prolog. Explain.
17. Name something you dislike about Prolog. Explain.
18. Did you enjoy this lab? Which aspects did you like and/or dislike?
19. Approximately how many hours did you spend on this lab?
20. Do you think you will use Prolog again? For which type(s) of project(s)?

Each student will complete and submit this assignment individually or in a two-person team. Do not consult with others. However, you are encouraged to use the Internet to learn any aspect of Prolog you need to complete the assignment, but not to answer the questions asked in this lab.

Comment your program appropriately. Intelligent comments and a clean, readable formatting of your code accounts for 20% of your grade.

Save the final version of your program and zip the source code and questions.txt into a file named [lastname]_[firstname].prolog_lab.zip.

We must be able to run your program from the command line with no arguments.

Submit your files to the Prolog Lab dropbox folder on BrightSpace. Submit your file before the due date as late submissions will not be accepted.

Total Assignment Points: 50, Available Extra Credit: 10 points, Total Grade Points: 7.5

The rubric for this assignment is as follows:

• 2 points each for questions 1 - 15, Total 30 points
• 5 points total for questions 16-20
• 10 points for working code, with no errors: All or nothing
• 5 points for documented code