📢Simplify Tensor Products with Epsilon-Delta

The core focus of the source is the application of the $\varepsilon-\delta$ -relation to transform the tensor expression $\varepsilon_{i j k} \varepsilon_{j k \ell}$ into a representation using the Kronecker delta. To master this, one must approach complex tensor identities by breaking them down into manageable, step-by-step calculations rather than attempting to solve them all at once. Furthermore, visualising the summation of individual products is essential, as it highlights the specific non-zero terms required to arrive at the final simplified value.