Patent – Infringement. The claimants brought bringing pre-emptive action for revocation of the defendants patents relating to computers and computer programming. In earlier proceedings, the court had found, among other things, that one of the defendant's patent had not been infringed by the claimant's devices. The defendant appealed. The Court of Appeal, Civil Division, in dismissing the appeal, held that the judge had correctly held that, on the true construction of one of the claims of the patent, there had been no infringement by any of the defendant's devices.