\[\varepsilon_{ijk} = \begin{cases} +1 & \text{if } (i,j,k) \text{ is } (1,2,3), (2,3,1) \text{ or } (3,1,2), \\ -1 & \text{if } (i,j,k) \text{ is } (3,2,1), (1,3,2) \text{ or } (2,1,3), \\ \;\;\,0 & ...εijk={+1if (i,j,k) is (1,2,3),(2,3,1) or (3,1,2),−1if (i,j,k) is (3,2,1),(1,3,2) or (2,1,3),0if i=j or j=k or k=i Después, usando la función tensordot, verificar la identidad∑iεijkεimn=δjmδkn−δjnδkm.
