Rule 58

Filing of reply statement and evidence

1 - If the patentee desires to contest the opposition, he shall leave at the appropriate office a reply statement setting out fully the grounds upon which the opposition is contested and evidence, if any, in support of his case within a period of two months from the date of receipt of the copy of the written statement and Opponent's evidence, if any by him under rule 57 and deliver to the opponent a copy thereof.

2 - If the patentee does not desire to contest or leave his reply and evidence within the period as specified in sub-rule (1), the patent shall be deemed to have been revoked.