1:- use_module(library(pita)).    2
    3
    4:- pita.    5
    6:- begin_lpad.    7
    8intelligent(_):0.5.
    9
   10good_marks(_):0.5.
   11
   12friends(_,_):0.5.
   13
   14% 1.5  Intelligent(x) => GoodMarks(x) 
   15factor1(X): 0.31025740516:- \+intelligent(X), \+good_marks(X).
   16factor1(X): 0.31025740516:- \+intelligent(X), good_marks(X).
   17factor1(X): 0.0692277845:- intelligent(X), \+good_marks(X).
   18factor1(X): 0.31025740516:- intelligent(X), good_marks(X).
   19
   20% 1.1 Friends(x, y) => (Intelligent(x) <=> Intelligent(y)) 1.1
   21factor2(X,Y): 0.150020804:- \+friends(X,Y).
   22factor2(X,Y): 0.150020804:- friends(X,Y), intelligent(X),intelligent(Y).
   23factor2(X,Y): 0.150020804:- friends(X,Y), \+intelligent(X),\+intelligent(Y).
   24factor2(X,Y): 0.049937588:- friends(X,Y), intelligent(X),\+intelligent(Y).
   25factor2(X,Y): 0.049937588:- friends(X,Y), \+intelligent(X),intelligent(Y).
   26
   27student(anna).
   28student(bob).
   29evidence:- factor1(anna),factor1(bob),factor2(anna,anna),
   30    factor2(anna,bob),factor2(bob,anna),factor2(bob,bob).
   31
   32ev_intelligent_bob_friends_anna_bob:-
   33    intelligent(bob),friends(anna,bob),evidence.
   34
   35:- end_lpad.