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