:- use_module(library(pfl)).

:- clpbn_horus:set_solver(fove).
%:- clpbn_horus:set_solver(hve).
%:- clpbn_horus:set_solver(bp).
%:- clpbn_horus:set_solver(cbp).

:- yap_flag(write_strings, off).


friends(P1, P2) :-
    person(P1),
    person(P2),
    P1 \= P2.

person @ 3.

markov smokes(P)::[t,f] , cancer(P)::[t,f] ; [0.1, 0.2, 0.3, 0.4] ; [person(P)].

markov friend(P1,P2)::[t,f], smokes(P1)::[t,f], smokes(P2)::[t,f] ; [0.5, 0.6, 0.7, 0.8, 0.5, 0.6, 0.7, 0.8] ; [friends(P1, P2)].

% ?- smokes(person_1, t), smokes(person_2, f), friend(person_1, person_2, X).