1:- use_module(library(pita)).
2
3:- pita.
4
5:- begin_lpad.
6
7? :: marketed(theo).
8? :: marketed(bernd).
9? :: marketed(guy).
10? :: marketed(ingo).
11? :: marketed(angelika).
12? :: marketed(martijn).
13? :: marketed(laura).
14? :: marketed(kurt).
15
16utility(marketed(theo),-2).
17utility(marketed(bernd),-2).
18utility(marketed(guy),-2).
19utility(marketed(ingo),-2).
20utility(marketed(angelika),-2).
21utility(marketed(martijn),-2).
22utility(marketed(laura),-2).
23utility(marketed(kurt),-2).
24
25utility(buys(theo),5).
26utility(buys(bernd),5).
27utility(buys(guy),5).
28utility(buys(ingo),5).
29utility(buys(angelika),5).
30utility(buys(martijn),5).
31utility(buys(laura),5).
32utility(buys(kurt),5).
33
340.2 :: buy_from_marketing(_).
350.3 :: buy_from_trust(_,_).
36
37trusts(X,Y) :- trusts_directed(X,Y).
38trusts(X,Y) :- trusts_directed(Y,X).
39
40trusts_directed(bernd,ingo).
41trusts_directed(ingo,theo).
42trusts_directed(theo,angelika).
43trusts_directed(bernd,martijn).
44trusts_directed(ingo,martijn).
45trusts_directed(martijn,guy).
46trusts_directed(guy,theo).
47trusts_directed(guy,angelika).
48trusts_directed(laura,ingo).
49trusts_directed(laura,theo).
50trusts_directed(laura,guy).
51trusts_directed(laura,martijn).
52trusts_directed(kurt,bernd).
53
54buys(X):-
55 marketed(X),
56 buy_from_marketing(X).
57buys(X):-
58 trusts(X,Y),
59 buy_from_trust(X,Y),
60 buys(Y).
61
62:- end_lpad.
63