Let \(A = \left[ {\begin{array}{*{20}{c}} 4&6&{ - 1}\\ 3&0&2\\ 1&{ - 2}&5 \end{array}} \right]\),\(B = \left[ {\begin{array}{*{20}{c}} 2\\ 0\\ { - 1} \end{array}\begin{array}{*{20}{c}} 4\\ 1\\ 2 \end{array}} \right]\)and C = [3 1 2]. The expression which is not defined is