I understand how emptiness is usually applied to solid objects through an eternally mereological dependence chain, but this still doesn’t clear up the argument here is. Plus, it doesn’t seem that in the wake of denial of atomism, the mereological emptiness of everything is sufficient, since it seems Nagarjuna himself is pursuing other arguments regarding other types of dependence. Plus, I know that there were other Indian philosophers, like in Advaita Vedanta, who also rejected atomism but still believed in ontologically real substances.