*/
public IntSet directlyLearnable(IntSet indices) {
if (indices.isEmpty()) return Ints.EMPTY_SET;
else if (valid(indices)) {
final IntSet ret = new IntBitSet(trace.length);
ret.addAll(indices);
TOP: for(int i = axioms, length = trace.length; i < length; i++) {
int[] resolvent = trace[i];
if (resolved(i)) {
for(int j = 1, antes = resolvent[0]; j <= antes; j++) {
if (!indices.contains(resolvent[j])) {