In Einstein notation, the duplication from the i index indicates the sum on i. The earlier is then denoted εijkεimn = δjmδkn − δjnδkm.These Qualities are essential for knowledge the habits on the tensor in various coordinate units.ε i j ε i n = δ j n displaystyle varepsilon _ ij varepsilon ^ in = delta _ j ^ n The Levi-Civita symbol enab