Listed​(AngouriMath.​Entity,​System.​Boolean)

{ x in S : p } for a set of numbers S, listed or written as intervals
where that takes no search: over a listed S, the members at which p is
decided true; over the reals, an interval or a set of whole numbers, S met with
the solutions of p, where p compares rational functions of x of
low degree with numbers for coefficients, or is an equation in moduli of linear
functions, which the solvers answer exactly. A set of whole numbers is met only where
that comes out listed. Sullivan and Mackey's §3.3.3-4, Prop 3.9.6 and Prob 3.11.4:
{ x in ZZ+ : x + 8/x <= 6 } is { 2, 3, 4 }, and
{ x in RR : x^2 - 2 = 0 } is { -sqrt(2), sqrt(2) }.
https://github.com/asc-community/AngouriMath/issues/1409