56 CAP. 400] Patents prescribed manner bring an action against him in the Court for any such relief as is mentioned in subsection (2). (2) Unless in any action brought by virtue of this section the defendant proves that the acts in respect of which proceedings were threatened constitute or, if done, would constitute, an infringement of a patent or of rights arising from the publication of a complete spec­ ification in respect of a claim of the specification not shown by the plaintiff to be invalid, the plaintiff shall be entitled to the following relief, that is to say: (a) a declaration to the effect that the threats are unjustifiable; (b) an injunction or interdict against the continuance of the threats; and (c) such damages, if any, as he has sustained thereby. (3) For the avoidance of doubt, it is hereby declared that a mere notification of the existence of a patent does not constitute a threat of proceedings within the meaning of this section. (4) The defendant in any such action as aforesaid may apply, by way of counter-claim in the action, for any relief to which he would be entitled in a separate action in respect of any infringement by the plaintiff of the patent to which the threats relate. (As amended by G.N. No. 185 of 1964) Powerof Court to make declaration as to non­ infringement 57. (l) A declaration that the use by any person of any process, or the making or use or sale by any person of any article, does not or would not constitute an infringement of a claim of a patent may be made by the Court in proceedings between that person and the paten­ tee or the holder of an exclusive licence under the patent, notwith­ standing that no assertion to the contrary has been made by the paten­ tee or licensee, if it is shown­ (a) that the plaintiff has applied in writing to the patentee or licensee for a written acknowledgment to the effect of the declaration claimed, and has furnished him with full partic­ ulars in writing of the process or article in question; and (b) that the patentee or licensee has refused or neglected to give such an acknowledgment. (2) The costs of all parties in proceedings for a declaration brought by virtue of this section shall be ordered as the Court may deem fit: Provided that a patentee or holder of an exclusive licence under the patent shall not be liable for any costs unless he enters an appear­ ance and takes part in the proceedings. (3) The validity of a claim of the specification of a patent shall not be called in question in proceedings for a declaration brought by