UNITED NATIONS (AP) — It's killer robots versus super intelligence. Visions of the future straight out of comic books are playing out at the United Nations as world leaders talk about the threat — or promise — of artificial intelligence. Once again it was Donald Trump against the U. N, chief and other leaders on a pressing issue involving science and the future, echoing ongoing disputes over the threat of climate change. Armed with a new U. N. science report that warns of a slight but of...