x1 (text) is a lujvo with meaning x2 and arguments x3, and which is constructed from tanru/veljvo x4 such that each element of the veljvo is ultimately only a cmavo (including "{zei}", "{ke}"/"{ke'e}", "{bo}", etc.), gismu, or rafsi of such cmavo or gismu.
The date [day,week,month,year] x1=d1=k1 is recurrence/repetition of the date [day,week,month,year] of the first event x2=d2, for the x3=k3'rd time, in system x3.
x1 is an eigenvalue (or zero) of linear transformation/square matrix x2, associated with/'owning' all vectors in generalized eigenspace x3 (implies neither nondegeneracy nor degeneracy; default includes the zero vector) with 'eigenspace-generalization' power/exponent x4 (typically and probably by cultural default will be 1), with algebraic multiplicity (of eigenvalue) x5
x1 (set, group, structure, category, class, etc.) has cardinality less than or equal to aleph-null; x1 is mathematically countable (including the option of being finite).
x1 is utility, the total subjective well-being/pleasure/happiness (or reduction in suffering) generated by action/event/state x2 according to psychological/philosophical/economic theory x3.
x1 is a logical language group/cluster/team showing common property (ka) x2 due to set x3 (a specification of the complete membership) linked by relations x4
x1 is a positive number (greater than zero (0)), understood as a member of an ordered set with additive identity, such as the typical structure on the set of all real numbers.
x1 is a negative number (less than zero (0)), understood as a member of an ordered set with additive identity, such as the typical structure on the set of all real numbers.