the situation changes completely for higher-order tensors in formula_108 with formula_109 and all formula_110. for simplicity in notation, assume without loss of generality that the factors are ordered such that formula_111. let formula_112denote the set of tensors of rank bounded by formula_6. then, the following statement was proved to be correct using a computer-assisted proof for all spaces of dimension formula_114, and it is conjectured to be valid in general: