Apple on Monday revealed what it's been working on in artificial intelligence at its annual Worldwide Developers Conference in Cupertino, Calif. WWDC showed off demos of its redesigned Siri, which can speak back and forth with the user, a major improvement over previous versions of the assistant. In a demo, Siri was able to check concert dates, set a reminder to buy tickets, and even get directions to pick up a friend on the way to the concert venue.But the announcement also highlighted that App...