30. Any application for a certificate of addition may, prior to its grant, be turned into a patent application at the request of the applicant or his agent. Such transformation shall take effect from the date of filing of the application for a certificate of addition. Chapter II Filing of patent applications and grant of patents SECTION I FILING OF PATENT APPLICATIONS 31. Anyone seeking an invention patent must file with the entity responsible for industrial property a patent application in the following conditions: The patent application must contain on the date on which it is filed: (a) a patent request, mentioning the title of the invention, the content of which shall be fixed by regulation; (b) proof of payment of the prescribed fees. Patent applications which do not contain the documents provided for under (a) and (b) above shall not be entertained at the actual time of filing. The necessary formalities and the documents to be attached to the documents referred to in (a) and (b) above, in particular the documents relating to the description of the invention and the related claims, shall be fixed by regulation. Where the patent application contains the documents referred to in (a) and (b) above, the patent application as provided for in (a) above shall be entered in chronological order of filing in the National Register of Patents referred to in Article 58.1 below, with a filing date and number. 32. If, on the date of filing, the patent application does not contain one or more documents to be attached to the documents referred in to (a) and (b) above, the list of which shall be fixed by regulation pursuant to Article 31.4 above, the applicant or his agent shall have three months as from the filing date, to correct any shortcomings in the file. Applications which have been so corrected within the time period set shall retain the date of initial filing. The time period of three months shall be a clear time period. If the last day is a public holiday or not a working day, the time period shall be extended until the first following working day. 33. A receipt bearing the date on which the documents referred to in Article 31.2 and 31.4 above have been provided shall be issued to the applicant or his agent as soon as he has filed the application. 34. The description of the invention shall include: (1) an indication of the technical field to which the invention relates; (2) an indication of the prior art, which is known to the applicant and may be considered useful for understanding the invention; (3) an explanation of the invention, as characterized in the claims, making it possible to understand both the technical problem and the solution provided; the advantages of the invention in relation to prior art shall be indicated, as appropriate;