mekso at-most-4-ary operator: integer lattice ball; the set of all points belonging to the intersection of Z^{n} with the closure of the ball that is centered on X_{1} and has radius X_{2} in metric X_{3}, where Z is the set of all integers and where, for any set A and non-negative integer n,
A^{n} is the set of all n-tuples such that each coordinate/entry/term belongs to A, and where the dimensionality n = X_{4}..

X_{3} defaults to whatsoever metric is specified to apply but which is outside of this function; contextless default is discrete, taxicab, Euclidean, or Chebyshev maximum norm; for explicit specification, use "mau'au"-"zai'ai" quotation. X_{2} defaults to 1. X_{1} defaults to 0 = (0,...,0), where the rhs is an X_{4}-tuple, id est the origin. See also: "mi'i", "ci'au'u".