x_{1} (amount/value (li/ni) or labelled entity) is the (mutual) difference between/change in (states/realizations of/output from) general and relevant idea/object or subject of interest or function/aspect/property/topic/dependent parameter/dependent variable x_{2} under or due to a change in (independent) parameter/variable/index/identification/ownership/property/aspect x_{3} (generic name) to (later) specific state/realization/value/person/entity/meaning x_{4} (type and dimensions match those of x_{3}) from (earlier) specific state/realization/value/person/entity/meaning x_{5} (type and dimensions match that of x_{3}), under circumstances/conditions/with(in) scope/with caveats x_{6}.

Especially in reference to incremental or quantized (or discretely observed) changes. x_{2} is an x_{1}-type-valued function of x_{3}; x_{4} and x_{5} are realizations of x_{3} (therefore, all three share type). For example, x_{1} could be some value with dimensions of currency/money/monetary value measured in real numbers, x_{2} could be a specific business' profit from certain sales, x_{3} may be time (so, x_{2} would be the profit over time, measured in a real number of units of currency), and x_{4} and x_{5} would be specific times - such as today and yesterday, respectively. Ideally, all factors, variables, conditions, etc. other than x_{3} should remain constant or there should be a control group/population which records the effects of changes in other factors, variables, conditions, etc.; however, in real life, things can be more complicated or messy and it is hard to ensure that all factors are accounted for (especially in social experiments and business); x_{5} records those other conditions or specifies the scope (for example: subjects, time, and location) of the 'experiment'. Typically, x_{4} will be temporally later than x_{5}, but this need not be the case; in any case, x_{4} is taken to be the latter state (etc.) under consideration in the present analysis in the context of this word's usage (in some sequence). x_{1} could be "0" (whatsoever that means) - it could even be identically so; in other words, there need be no change or mutual difference, even in principle (the function/object could be constant); and this fact could even be known a priori. See also: "sumji" / "selsumji".

- velri'ekempintu'a in sense "of a river"
- x
_{1}is a relatively flat alluvial plain/river delta between (mostly) terminal branches of river x_{3}on landmass x_{4}, near or touching terminal point/boundary x_{2}.

- zdeltadirake
- x
_{1}is the Dirac delta function (generalized), defined on structure x_{2}(contextless default is probably the field of real numbers), yielded by family of distributions x_{3}(contextless default is probably Gaussians centered at 0 and which enclose unit area) - zdeltakronekre
- x
_{1}is a Kronecker delta function defined on structure x_{2}which evaluates to one for any argument belonging to subset x_{3}and which evaluates to zero otherwise

- ca'o'e
*(exp!)* - mekso 4-nary operator: spherical harmonics on colatitudinal/polar angle a and azimuthal/longitudinal angle b of unassociated order c and associated order d.
- ma'au
*(exp!)* - Binary mekso operator: uniform probability A(X
_{2)u(X}for input (X_{1,X}where X_{1}is a number and X_{2}is a set or space. (See notes for details). - te'i'ai
*(exp!)* - 6-ary mekso/mathematical operator: Heaviside function/step/Theta function of a, of order b, in structure c, using distribution d, within approximated limit e, with value f_b at 0
- cia'o'e
- mekso 4-nary operator: spherical harmonics on colatitudinal/polar angle a and azimuthal/longitudinal angle b of unassociated order c and associated order d.