Composite numbers (∀2) of any odd multiple (2) family (including the first prime number 3) become the poles of (2∈ ) of the open covering set, so (∀2∉ ), but (∀2⊂) is the neighborhood:
Any odd multiple (2) family composite number (∀ 2) (including the first prime number 3) becomes the pole of (2 ∈) of the open cover set, so (∀ 2 ∉), but (∀ 2 ⊂) is the neighborhood:
Any odd multiple of (2) family complex number (2) (including the first prime number 3) becomes the pole of (2∈) of the open covering set, so (2), but (2) is a neighborhood: