Complex sentence: Another problem is that the symbol\\ doteq should not be used when an inner product is expressed as a sum of coordinate products, as currently done in many places--although the terms in the sum depend on the basis set, the expression itself does not.
Split into simpler sentences: Another problem is that the symbol\\ doteq should not be used when an inner product is expressed as a sum of coordinate products, as currently done in many places. Although the terms in the sum depend on the basis set, the expression itself does not.