public override Predicate exec( Prolog engine )
{
Term a1, a2, a3, a4;
Predicate p1;
a1 = engine.aregs[1].Dereference();
a2 = engine.aregs[2].Dereference();
a3 = engine.aregs[3].Dereference();
a4 = engine.aregs[4].Dereference();
Predicate cont = engine.cont;
if ( !s1.Unify(a3, engine.trail) ) return engine.fail();
p1 = new Predicates.Close_Line_4(a1, a2, s1, a4, cont);
return new Predicates.Free_Line_3(a1, a2, s1, p1);
}
public override Predicate exec( Prolog engine )
{
Term a1, a2, a3, a4, a5, a6;
Predicate p1, p2, p3, p4, p5;
a1 = engine.aregs[1].Dereference();
a2 = engine.aregs[2].Dereference();
a3 = engine.aregs[3].Dereference();
a4 = engine.aregs[4].Dereference();
Predicate cont = engine.cont;
if ( !s1.Unify(a3, engine.trail) ) return engine.fail();
if ( !s2.Unify(a4, engine.trail) ) return engine.fail();
a5 = engine.makeVariable();
a6 = engine.makeVariable();
p1 = new Predicates.Close_Line_4(a1, a2, s1, s4, cont);
p2 = new Predicates.Line_3(a6, a1, s3, p1);
p3 = new Predicates.dollar_plus_3(a2, s3, a6, p2);
p4 = new Predicates.Line_3(a2, a1, s3, p3);
p5 = new Predicates.Line_3(a5, a2, s1, p4);
return new Predicates.dollar_plus_3(a1, s3, a5, p5);
}
