:- use_module('../metagol').

%% first-order background knowledge
mother(ann,amy).
mother(ann,andy).
mother(amy,amelia).
mother(linda,gavin).
father(steve,amy).
father(steve,andy).
father(gavin,amelia).
father(andy,spongebob).

%% predicates that can be used in the learning
prim(mother/2).
prim(father/2).

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

%% learning task
a :-
  %% positive examples
  Pos = [
    grandparent(ann,amelia),
    grandparent(steve,amelia),
    grandparent(ann,spongebob),
    grandparent(steve,spongebob),
    grandparent(linda,amelia)
  ],
  %% negative examples
  Neg = [
    grandparent(amy,amelia)
  ],
  learn(Pos,Neg).

%% open file with prolog and run
%% ?- a