if (remainder instanceof Sum)
remainder = ((Sum) remainder).remove(i);
else remainder = Complex.ZERO;
}
}
Tensor symbolicPart = ((Sum) c).select(symbolicPositions.toArray());
symbolicPart = factorSymbolicTerm(symbolicPart);
if (remainder instanceof Sum) {
SumBuilder sb = new SumBuilder(remainder.size());
for (Tensor tt : remainder)
sb.put(factorSymbolicTerms(tt));