  We rigorously state the connection between the EHZ-capacity of convex
Lagrangian products $K\times T\subset\mathbb{R}^n\times\mathbb{R}^n$ and the
minimal length of closed $(K,T)$-Minkowski billiard trajectories. This
connection was made explicit for the first time by Artstein-Avidan and Ostrover
under the assumption of smoothness and strict convexity of both $K$ and $T$. We
prove this connection in its full generality, i.e., without requiring any
conditions on the convex bodies $K$ and $T$. This prepares the computation of
the EHZ-capacity of convex Lagrangian products of two convex polytopes by using
discrete computational methods.
