What does the preliminary examination of an application for a patent for invention include?

According to the provisions of the Patent Law, the contents of the preliminary examination of the invention patent include: 1, whether the applicant's application documents are complete, and whether the writing conforms to the provisions of the Patent Law and its implementing rules; 2. The applicant's identity is legal and all kinds of certificates are complete. If the applicant is a foreigner, whether to entrust an agent according to law; 3. Whether the invention-creation for which the patent is applied violates national laws, social morality or harms public interests, and whether it belongs to the object for which the patent right is not granted; 4. Whether the applicant has paid the application fee, etc.