// This isn't pretty, but I swear there's
// not an easy way...
private void setupAlphabet (Instance inst)
{
LabelsAssignment lblseq = (LabelsAssignment) inst.getTarget ();
factors = new TIntArrayList [lblseq.numSlices ()];
for (int i = 0; i < lblseq.numSlices (); i++) {
LabelAlphabet dict = lblseq.getOutputAlphabet (i);
factors[i] = new TIntArrayList (dict.size ());
for (int j = 0; j < dict.size (); j++) {
int idx = alphabet.lookupIndex (dict.lookupObject (j));