/*  Filename:    course2.pro
 *
 *  Programmer:  Br. David Carlson
 *
 *  Date:        March 4, 1991
 *
 *  Description: This program creates a small database on course
 *  offerings and has 2 rules to extract information on these.
 */

instructor(cs255, br_david).
instructor(cs110, mr_morrison).
instructor(cs111, br_david).

offered(cs111, semester(spring, 1991)).
offered(cs255, semester(spring, 1991)).
offered(cs110, semester(fall, X)).  /* true for any year X */

/* Report's on Br. David's Spring 1991 course(s). */
report(Course) :- instructor(Course, br_david), 
     offered(Course, semester(spring, 1991)).

course_list(Course, Teacher, Term, Year) :- 
     instructor(Course, Teacher), offered(Course, semester(Term, Year)).