1/* 2Computing the probability of a path between two nodes in a probabilistic graph. 3Each edge has a probability of being present. 4From 5L. De Raedt, A. Kimmig, and H. Toivonen. ProbLog: A probabilistic Prolog and 6its application in link discovery. In International Joint Conference on 7Artificial Intelligence, pages 2462-2467, 2007. 8*/ 9:- use_module(library(pita)). 10 11:- if(current_predicate(use_rendering/1)). 12:- use_rendering(c3). 13:- use_rendering(graphviz). 14:- use_rendering(table,[header(['Multivalued variable index','Rule index','Grounding substitution'])]). 15:- endif. 16 17:- pita. 18 19:- begin_lpad. 20 21% path(X,Y) is true if there is a path between nodes X and Y 22% edge(a,b) indicates that there is an edge between a and b 23 24path(X,X). 25% there is surely a path between a node and itself 26 27path(X,Y):- 28 edge(X,Z),path(Z,Y). 29% there is surely a path between X and Y if there is another node Z such that 30% there is an edge between X and Z and there is a path between Z and Y 31 32edge(a,b)0.2. 33% there is an edge between a and b with probability 0.2 34edge(b,e)0.5. 35edge(a,c)0.3. 36edge(c,d)0.4. 37edge(d,e)0.4. 38edge(a,e)0.1. 39 40:- end_lpad. 41 42graph(digraph([rankdir='LR'|G])):- 43 findall(edge((A -> B),[label=P]), 44 clause(edge(A,B,_,_),(get_var_n(_,_,_,_,[P|_],_),_)), 45 G).

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`prob(path(a,e),Prob)`

. % what is the probability that a and e are connected? % expected result 0.22888 ?-`prob(path(a,e),Prob)`

,`bar(Prob,C)`

. % what is the probability that a and e are connected? % expected result 0.22888 ?-`graph(G)`

. % shows the probabilistic graph?-

`bdd_dot_string(path(a,e),BDD,Var)`

. % What is the BDD for query`path(a,e)`

? % A solid edge indicates a 1-child, a dashed edge indicates a 0-child and % a dotted % edge indicates a negated 0-child. % The table Var contains the associations between the rule groundings and the % multivalued variables.*/