begin%classes%
class(id, name) :- id = 1, name = "CSC 421".
class(id, name) :- id = 2, name = "CSC 383".
class(id, name) :- id = 3, name = "CSC 212".
class(id, name) :- id = 4, name = "CSC 211".
class(id, name) :- id = 5, name = "CSC 202".

requires(rqid,rdid) :- rqid = 1, rdid = 2.
requires(rqid,rdid) :- rqid = 1, rdid = 5.
requires(rqid,rdid) :- rqid = 2, rdid = 3.
requires(rqid,rdid) :- rqid = 3, rdid = 4.

rec_req(a,b) :- requires(a,b).
rec_req(a,b) :- requires(a,c), rec_req(c,b).
end%classes%