TO ALL MATHEMATICIANS WHO HAVE PRELIMINARILY PREREGISTERED FOR THE INTERNATIONAL CONGRESS OF MATHEMATICIANS 1998 IN BERLIN Eleventh Circular Letter, April 7, 1997 (Special Announcement) ADDENDUM Subject: ICM98-CL11: Riemann conjecture solved? Dear colleague: The message concerning the Riemann conjecture I received looked a bit suspicious (unnamed bright young physicist), but I was advised by serious people that there could be some truth in it. After sending out the circular letter I was showered by e-mails pointing out that this is (most likely) an April Fool's joke, though a good one, based indeed on significant new work by Alain Connes. Sorry for bothering you. Sincerely Martin Groetschel