int numArcs = olds.getNumArcs();
for (int j = 0; j < numArcs; j++) {
Arc olda = olds.getArc(j);
State next = stateMap[olda.getNextState().getId()];
Arc newa = new Arc(olda.getIlabel(), olda.getOlabel(),
semiring.reverse(olda.getWeight()), news);
next.addArc(newa);
}
}
ExtendFinal.undo(fst);