University of Florida researchers in the Department of Materials Science and Engineering have invented a technique that rapidly detects traces of TNT (Today, Spring 2005). The method, which involves shining a laser on a potentially contaminated object, provides instantaneous results and gives no false positives. In this application, a false positive would occur if the laser detected traces of TNT when, in fact, no TNT were actually present on the object. Let A be the event that the laser light detects traces of TNT. Let B be the event that the object contains no traces of TNT. The probability of a false positive is 0.

Required:
Write this probability in terms of A and B using symbols such as U, ∩ and |.