Set (Subscript[N, 𝒜])(p,ϵ)={q ϵ 𝒜 : d(q,p) < ϵ} = B(p,ϵ)⋂𝒜 where B(p,ϵ)⋂𝒜 ⊂  (ℝ^n)is the open ϵ-ball around p

Input: data set 𝒜 ⊂ (ℝ^n), p ϵ 𝒜, ϵ > 0;
Output: (Subscript[N, 𝒜])(p,ϵ);
Submodules: none needed

Neps[A_,x_,eps_]:=Nearest[A,x,{All,eps},DistanceFunction->(Norm[#1-#2,2]&)]