John Woldemar Cowan, The Complete Lojban Language — Chapter 6 - To Speak Of Many Things… (1997)
“ In the case of mass and set descriptors, a single rule suffices for each: reference to a mass is implicitly a reference to some part of the mass; reference to a set is implicitly a reference to the whole set. Masses and sets are inherently singular objects: it makes no sense to talk about two distinct masses with the same components, or two distinct sets with the same members. Therefore, the largest possible outer quantifier for either a set description or a mass description is “piro”, the whole of it. ”
