:- use_module(library(pfl)). :- set_pfl_flag(solver,fove). %:- set_pfl_flag(solver,fove). t(ann). t(dave). % p(ann,t). bayes p(X)::[t,f] ; [0.1, 0.3] ; [t(X)]. % use standard Prolog queries: provide evidence first. ?- p(dave,t), p(ann,X). % ?- p(ann,X).