===================================================
'Clancy Bouvier'=='Jacqueline Gurney'
'Carnival Woman'=='Abraham Simpson' |
| 'Abraham Simpson'=='Penelope Olsen' +------------------+--------------+
| | | | |
'Herbert Powell' 'Homer Simpson'=='Marge Bouvier' 'Patricia Bouvier' 'Selma Bouvier'
| |
+-----------------+----------------+ 'Ling Bouvier'
| | | (adopted)
'Bart Simpson' 'Lisa Simpson' 'Maggie Simpson'
===================================================
(A==B means that A married B; their children are listed underneath the ==. Note that 'Abraham Simpson' married twice. If you are into this Simpsons thing, you will notice that I omitted Amber Simpson from the tree because it is just flat weird that she was married to both Homer and Abraham Simpson. )-:
Part 1(a).
Make a file named simpsons.pl to hold the Prolog clauses that model the above tree structure.
Here is part of the coding;
you do the rest:
===================================================
female('Carnival Woman').
male('Abraham Simpson').
female('Penelope Olsen').
male('Herbert Powell').
male('Homer Simpson').
male('Bart Simpson').
/* ...you do the remainder of the gender clauses;
consult the above web link if you are unsure about any person's gender. */
female('Ling Bouvier').
/* predicate parents(CHILD, FATHER, MOTHER) asserts that
CHILD has FATHER as its father and MOTHER as its mother:
*/
parents('Herbert Powell', 'Abraham Simpson', 'Carnival Woman').
parents('Homer Simpson', 'Abraham Simpson', 'Penelope Olsen').
parents('Bart Simpson', 'Homer Simpson', 'Marge Bouvier').
/* ...you do the remainder of the parent clauses up to this last one: */
parents('Ling Bouvier', none, 'Selma Bouvier')
/* sister(X, Y) defines that X has Y as a sister if
Y is female, X's and Y's parents are the same, and X != Y */
sister(X,Y) :- female(Y),
parents(X,Father,Mother), parents(Y,Father,Mother),
X \= Y.
Run this test:
?- sister('Marge Bouvier', Z).
type semicolons till the prover prints False (or No). You should obtain:
Z = 'Patricia Bouvier' ;
Z = 'Selma Bouvier' ;
False
Now you are ready to do the rest of Question 1.
Part 1(b).
Code this Prolog predicate and add it to simpsons.pl:
X has A as an aunt if
X's father has A as a sister or if X's mother has A as a sister:
/* aunt(X, A) defines that X has A as an aunt */
(Hint: Code your definition of aunt so that it matches exactly
what I said above.)
Test your definition with at least these test cases:
?- aunt('Bart Simpson', Z).
Z = 'Patricia Bouvier' ;
Z = 'Selma Bouvier' ;
false.
?- aunt(X, 'Patricia Bouvier').
X = 'Bart Simpson' ;
X = 'Lisa Simpson' ;
X = 'Maggie Simpson' ;
X = 'Ling Bouvier'.
?- aunt(X,Y).
(there should be a long list!)
Copy and
paste your test cases and their outputs into a txt file
named simpsons.txt.
Part 1(c).
Code these two Prolog predicates and add them to simpsons.pl:
/* halfBrother(X, Y) defines that X and Y are half brothers. */
/* brother(X, Y) defines that X and Y are brothers. */
Test your definitions with at least these test cases:
?- brother('Homer Simpson', Z).
?- halfBrother(X,Y).
Copy and paste your test cases and outputs into
simpsons.txt.
Part 1(d).
Code these Prolog predicates and add them to simpsons.pl:
/* niece(X, Y) defines that X has Y as a niece. */
/* nephew(X, Y) defines that X has Y as a nephew. */
?- niece('Patricia Bouvier', N).
?- niece(X, Y).
?- nephew(X, 'Bart Simpson').
Copy and paste your test cases and their outputs into
simpsons.txt.
Place this library database into a file named library.pl:
===================================================
/* Functor for defining book and dvd objects:
ITEM ::= book(TITLE, AUTHOR) | dvd(TITLE)
where TITLE and AUTHOR are strings
Predicates that define ownership of an object
and when an object is borrowed from the library:
PRED ::= owns(KEY, ITEM) | borrowed(KEY, PERSON, DUEDATE)
where KEY is an atom that begins with k
ITEM is defined above
PERSON is an atom
DUEDATE is an int
*/
owns(k0, book('David Copperfied', 'Charles Dickens')).
owns(k1, book('Tale of Two Cities', 'Charles Dickens')).
owns(k2, book('Tale of Two Cities', 'Charles Dickens')).
owns(k3, dvd('Tale of Two Cities')).
owns(k4, book('Moby Dick', 'Herman Melville')).
owns(k5, dvd('Brothers Karamazov', 'Fyodor Dostoyevski')).
borrowed(k2, 'Homer', 10).
borrowed(k4, 'Homer', 20).
borrowed(k3, 'Lisa', 40).
borrowed(k0, 'Lisa', 45).
borrowed(k5, 'Homer', 90).
/* overdue holds true when ItemKey is borrowed (by Who) and is due earlier than Today */
overdue(ItemKey, Today) :- borrowed(ItemKey, _, DueDate),
Today > DueDate.
/* fine calculates the int value of HowMuch when ItemKey is overdue as of Today */
fine(ItemKey, Today, HowMuch) :- overdue(ItemKey, Today),
borrowed(ItemKey, _, DueDate),
HowMuch is Today - DueDate.
/* getBorrowed(Who, ItemList) calculates a list of KEYs
of all the items Who has borrowed. */
getBorrowed(Who, ItemList) :- findall(Key, borrowed(Key, Who, _), ItemList).
===================================================
Part 2(a).
Write this definition in Prolog and add it to library.pl:
/* getOverdue(Who, Today, ItemList) calculates ItemList, which is a list of KEYs
of all the items Who has borrowed that are overdue as of Today. */
Test your coding on at least these examples:
?- getOverdue('Homer', 25, List).
List = [k2, k4].
?- getOverdue('Lisa', 25, List).
List = [].
?- getOverdue(_, 50, List).
List = [k2, k4, k3, k0].
Copy and
your test cases and their outputs into a txt file
named library.txt.
Part 2(b).
Write this definition in Prolog and add it to library.pl:
/* totalfine(Who, Today, Amount) calculates Amount, which is an int
that states the total fine that Who owes due to overdue items as of Today */
(Hint: you must write a helper predicate that uses list-pattern matching,
like that used in the definition of printTitles
in the example program, lib.pl, posted on the Lectures web page.)
Test your coding on at least these examples:
?- totalfine('Homer', 25, Amt).
Amt = 20.
?- totalfine('Lisa', 25, Amt).
Amt = 0.
?- totalfine(_, 100, Total).
Total = 295.
Copy and
paste your test cases and their outputs into library.txt.
Do the questions in the order stated; each one builds on its predecessors.
When you load a Prolog program, verify there are no errors. (Often an error is triggered by a missing period or comma on the previous line.)
Use the listing and trace predicates to see what is happening inside Prolog when you use it.
Plan for several days to do the exercise, because if you get stuck, it might take a day to understand what to do.
If you are stuck, you are welcome to contact me, but don't wait till the last minute to do so. In particular, I cannot guarantee that I can respond to email questions on the due date, Saturday April 28.
When you are ready to submit, make a folder named Ex9, and place into it