This assignment is due on Monday, February 28, by 7:00 p.m. in the locking box in CS 189. The next assignment will be due on that date, too; we're just giving you some scheduling flexibility by extending the date of this one. Because this assignment involves an unfamiliar language and system, you should expect some difficulty and start early.

Summary: In this assignment you will get some experience with logic programming and Prolog.

Readings and review questions: You should know the answers to the review questions listed below, but you do not have to turn them in (except for questions 12 and 18; see part (a) below).

Chapter 15: 1-13, 15, 17-19

Prolog implementations: You can find Prolog implementations as follows:

For home use, you can download the free SWI-Prolog implementation from http://www.swi.psy.uva.nl/projects/SWI-Prolog/ .

On the ICS Unix machines, the Prolog software is cprolog. To use it, you need the line "module load cprolog" in your .cshrc file.

On the Macintosh, use Open Prolog, available from http://www.cs.tcd.ie/open-prolog/.

(a) In the review questions (not the problem set) on page 638 of the Sebesta text, do problems 12 and 18, answering each in one short sentence.

(b) Start up your Prolog system and, consulting its documentation as necessary, learn how to enter rules and goals.

Visit Dick Botting's Prolog tutorial site at Cal State San Bernardino, http://www.csci.csusb.edu/cs320/lab/08.html . It contains a series of short and interesting Prolog examples. Download and try two or three of them; then write a short paragraph describing the one that most impressed or surprised you.

This site isn't local, so don't panic if not everything works as expected. But if nothing works as expected, consult with your classmates or the TAs in the lab for help.

(c) Write a Prolog description of your family tree, going back at least to your grandparents (if possible). You may use some famous public family (such as the British royal family) if you prefer not to use your own. Here are more details:

(c.1) First, describe all the relationships in terms of these three predicates: parent(Parent,Child), male(Person), and female(Person).

(c.2) Then, define rules for these predicates:

• father(Parent,Child), mother(Parent,Child), child(Child,Parent), son(Child,Parent), daughter(Child,Parent)



• grandparent(GP,GC), grandmother(GM,GC), grandfather(GF,GC), grandchild(GC,GP), grandson(GS,GP), granddaughter(GD,GP)



• spouse(Husband,Wife), husband(Person,Wife), wife(Person,Husband).



• sibling(Person1,Person2), brother(Person,Sibling), sister(Person,Sibling).



• Similar rules for aunt, uncle, nephew, niece, and first cousin.



• (extra credit) Add rules for nth cousins, for cousins n times removed, and for greatⁿ-grandparents. You may need to find definitions of these terms on the web.

(c.3) Enter, run, and test your code. Turn in your code and transcripts of your tests.

(d) In the problem set (not the review questions) starting on page 638 of Sebesta, do one problem chosen from problems 5, 6, and 7. Feel free to work with your classmates on this problem.

(e) (extra credit) Try to identify in the Sebesta text some indication of his bias against Prolog or logic programming. Don't simply cite his descriptions of Prolog's disadvantages; that's not bias. Look instead for subtler wording or organizational points. Hint: Compare section titles.