Apple is suing a Chinese government agency and a domestic company over patent rights for its "Siri" personal assistant.

Apple launched the case against the State Intellectual Property Office, which is in charge of patent rights protection in China, and Shanghai's Zhizhen Network Technology, which developed software similar to Siri.

The Beijing No. 1 Intermediate People's Court is set to hear the case on Thursday, although there is no indication that the court will make a final ruling at the time.

What's the case?