Right now Prolog is available under medusa, but not under the other clients, so one must first do an ssh to medusa Here is a sample prolog source file, stored using the filename hanoi.pl:

% move all discs onto the center pole
% discs start piled in order at left
hanoi(N) :- move(N, left, center, right).

move(0, _, _, _) :- !.
move(N, A, B, C) :-
   M is N-1,
   move(M, A, C, B),
   inform(N, A, B),
   move(M, C, B, A).

inform(I, X, Y) :- write('move disc '), write(I), write(' from '),
   write(X), write(' to '), write(Y), nl.

% ssh medusa
password: (give password here)
medusa% pl
Welcome to SWI-Prolog (Version 3.2.9)
Copyright (c) 1993-1999 University of Amsterdam.  All rights reserved.

For help, use ?- help(Topic). or ?- apropos(Word).

?- consult(hanoi).
hanoi compiled, 0.00 sec, 1,676 bytes.

Yes
?- hanoi(1).
move disc 1 from left to center

Yes
?- hanoi(2).
move disc 1 from left to right
move disc 2 from left to center
move disc 1 from right to center

Yes
?- hanoi(3).
move disc 1 from left to center
move disc 2 from left to right
move disc 1 from center to right
move disc 3 from left to center
move disc 1 from right to left
move disc 2 from right to center
move disc 1 from left to center

Yes
?- halt.
medusa% 

spr03u(cs2213,  '001', 1900-mw,  maltrud).
spr03u(cs2213,  '002', 0930-tr,  maltrud).
spr03u(cs2413,  '001', 1000-mwf, maynard).
spr03u(cs2513,  '001', 1200-mwf, key).
spr03u(cs2733,  '001', 1300-mwf, wagner).
spr03u(cs3233,  '001', 1230-tr,  tian).
spr03u(cs3343,  '001', 1530-tr,  kwek).
spr03u(cs3723,  '001', 1200-mwf, wagner).
spr03u(cs3733,  '001', 1230-tr,  srobbins).
spr03u(cs3743,  '001', 1900-tr,  staff).
spr03u(cs3773,  '001', 1730-tr,  lo).
spr03u(cs4313,  '001', 1400-mw,  bylander).
spr03u(cs4363,  '001', 1000-mwf, wagner).
spr03u(cs4383,  '001', 1300-mwf, maynard).
spr03u(cs4753,  '001', 1730-mw,  yum).
spr03u(cs4913,  '000', arranged, staff).
spr03u(cs4953,  '001', 0930-tr,  srobbins).
spr03u(cs4993,  '000', arranged, staff).

semesteru(X, Y, Z, W) :- spr03u(X, Y, Z, W).
year('2003').
season('Spring').

• Database of upper-division CS courses. This is an initial very simple version to illustrate how the system works.
  • The Prolog file for courses for Spring 2003 (4.3 kbytes): spring03.pl.
  • Interactive session illustrating the program (3.5 kbytes): spring03.html.
• Database of upper-division CS courses. This is also a simplified version to help illustrate the principles.
  • The courses for Spring 2003 (0.8 kbytes): spring03.pl.
  • The file of fixed facts and rules that are independent of the semester (9.7 kbytes): general.pl.
  • The result of "running" this program, to produce a .html file (7.8 kbytes): spring03.html.
• The complete database for Spring 2003 courses. This is the full database of all courses. It is essentially the same as the previous example, but there are many additional details. This expanded version is about 5 times as large as the previous one.
  • Spring 2003 courses in Prolog (4.6 kbytes): spr03.pl.
  • The large file that handles all semesters (37.6 kbytes): general3.pl.
  • Resulting .html (32.7 kbytes): spr04.pl.