with two indices. The amazing relationship between these two symbols is that the product of epsilon ijk with epsilon lmn is equal to the determinant of a three-by-three matrix consisting of Kronecker deltas.
The Remarkable Relationship between the Levi-Civita Symbol and the Kronecker Delta | Deep Dive Maths
so this is 3, okay? Let me give you another example. If we look at epsilon ijk times epsilon ijk. We are under the Einstein summation convention, so that means we're summing from i = 1, 2, 3, j = 1, 2, 3 and k = 1, 2, 3, okay? So there's a lot of terms here. There is
Kronecker delta and Levi-Civita symbol | Lecture 7 | Vector Calculus for Engineers
what this object is what this object is it's epsilon ijk and it's defined to be it's epsilon ijk and it's defined to be
Cross Products Using Levi Civita Symbol