Indices indices;
int currentPivot, index, toTensorIndex;
while (!stack.isEmpty()) {
currentPivot = stack.pop();
indices = pc.get(currentPivot).getIndices();
contractions = fcs.contractions[currentPivot];
for (int i = contractions.length - 1; i >= 0; --i) {
index = indices.get(i);