(1) Every claim of a complete specification shall have effect from the date prescribed by this article in relation to that claim (in this Title referred to as the priority date); and a patent shall not invalidated by reason only of the publication or use of the invention, so far as claimed in any claim of the complete specification, on or after the priority date of that claim, or by the grant of another patent upon a specification claiming the same invention in a claim of the same or later priority date.
(2) Where the complete specification is filed in pursuance of a single application accompanied by a provisional specification which is treated by virtue of a direction under paragraph (4) of article 628 of this Code as a provisional specification, and the claim is fairly based on the matter disclosed in that specification, the priority date of that claim shall be the date of filing of the application.
(3) Where the complete specification is filed or proceeded with in pursuance of 2 or more applications accompanied by such specifications as are mentioned in the last foregoing article, and the claim is fairly based on the matter disclosed in one of those specifications, the priority date of that claim shall be the date of filing of the application accompanied by that specification.
(4) Where, under the foregoing provisions of this article, any claim of a complete specification would, but for this provision, have 2 or more priority dates, the priority date of that claim shall be the earlier or earliest of those dates.
(5) In any case to which paragraphs (2) to (4) of this article do not apply, the priority date of a claim shall be the date of filing of the complete specification.