In Einstein notation, the duplication from the i index indicates the sum on i. The earlier is then denoted ?ijk?imn = ?jm?kn ? ?jn?km.These Qualities are essential for knowledge the habits on the tensor in various coordinate units.? i j ? i n = ? j n displaystyle varepsilon _ ij varepsilon ^ in = delta _ j ^ n The Levi-Civita symbol enables the det