usePrologVariables: true.

/* 

Here is a ruleset Aleph learned on this testbed (the famous 'trains' testbed of Michalski):

 [Rule 1] [Pos coverage = 3, Neg coverage = 0]
    eastbound(A) :- has_car(A,B), wheels(B,3), has_car(A,C), load(C,triangle,1).

 [Rule 2] [Pos coverage = 3, Neg coverage = 0]
    eastbound(A) :- has_car(A,B), load(B,rectangle,1), has_car(A,C), load(C,triangle,1).

And here is what WILL produced:

 Rules learned by WILL on 11/6/07: (both cover 3 pos and 0 neg)
    eastbound(A) :- has_car(A, AA), load(AA, triangle, 1.0),                       has_car(A, AC), load(AC, rectangle, 1.0).
    eastbound(A) :- has_car(A, AA), load(AA, triangle, 1.0), shape(AA, rectangle), has_car(A, AD), load(AD, circle,    1.0).

  If rule length limited to five (including the head), get the following (same as Aleph).  Also ran on 11/6/07.
    eastbound(A) :- has_car(A, AA), load(AA, triangle, 1.0), has_car(A, AC), wheels(AC, 3.0).
    eastbound(A) :- has_car(A, AA), load(AA, triangle, 1.0), has_car(A, AC), load(AC, rectangle, 1.0).


*/

mode: eastbound(+train).
mode: short(   +car).
mode: closed(  +car).
mode: long(    +car).
mode: open_car(+car).
mode: double(  +car).
mode: jagged(  +car).
mode: shape(   +car, #shape)        maxPerInputVars=1.
mode: load(    +car, #shape, #int)  maxPerInputVars=1.
mode: wheels(  +car, #int)          maxPerInputVars=1.
mode: has_car(+train, -car).