order-2 tensors in formula_96, i.e., matrices, are not identifiable for formula_97. this follows essentially from the observation formula_98where formula_99 is an invertible formula_100 matrix, formula_101 , formula_102, formula_103 and formula_104. it can be shown that for every formula_105, where formula_40 is a closed set in the zariski topology, the decomposition on the right-hand side is a sum of a different set of rank-1 tensors than the decomposition on the left-hand side, entailing that order-2 tensors of rank formula_107 are generically not identifiable.