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 (text, image, page element) is infra/later-mentioned/subsequently mentioned/later/following/below/toward the bottom of the page/screen (flat and primarily two-dimensional display) relative to x2 (text, image, page element) on page/screen/in work x3 according to cultural convention x4.
x1 (text, image, page element) is supra/aforementioned/previous/earlier/preceding/above/toward the top of the page/screen (flat and primarily two-dimensional display) relative to x2 (text, image, page element) on page/screen/in work x3 according to cultural convention x4.
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 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.