Non-existence is not a fact, it is the absence of a fact, it is a derivative
concept pertaining to a relationship, i.e., a concept which can be formed or
grasped only in relation to some existent that has ceased to exist. (One can
arrive at the concept “absence” starting from the concept “presence,” in regard
to some particular existent(s); one cannot arrive at the concept “presence”
starting from the concept “absence,” with the absence including everything.)
Non-existence as such is a zero with no sequence of numbers to follow it, it is
the nothing, the total blank.