/*
 * Test on graph reachability
 */

/* This requires metagol
 * https://github.com/metagol/metagol
 */
 :- use_module('../metagol').

 %% metagol clause settings
 metagol:max_clauses(2).

 %% tell metagol to use the BK
 prim(edge/2).

 %% metarules
 metarule([P, Q], ([P, A, B]:- [[Q, A, B]])).
 metarule([P, Q], ([P, A, B]:-[[Q, A, C], [P, C, B]])).

 %% Background knowledge
 edge(a, b).
 edge(b, c).
 edge(c, a).
 edge(a, d).

 a:-
 	Pos = [p(a,b), p(a,c), p(a,a)],
 	learn(Pos, []).