Any odd multiple of (2) composite numbers (∀2) (including the first prime number 3) becomes the pole of (2∈ of the open covering set, so ∀2∉ , and ∀2⊂ is the neighborhood:
Any odd multiple (2) family composite number (∀ 2) (including the first prime number 3) becomes the pole of (2 ∈) of open cover set, so ∀ 2 ∉, and ∀ 2 ⊂ is a neighborhood:
The family complex number (2) (including the first prime number 3) with an arbitrary odd multiple of (2) becomes the pole of (2∈) of an open covering set, so 2 is a neighborhood: