x1 is a mass/team/aggregate/whole, together composed of components x2, considered jointly.
A description in x1 indicates of mass property(ies) displayed by the mass; masses may reveal properties not found in the individual set members that are massified, which themselves are not necessarily relevant to the mass property implicit in this bridi. See also bende, girzu, pagbu, cmavo list loi, lei, lai, ciste, cmima, kansa, tinci, mulgunma.