The paper by Sacks and Doyle that is the focus of this debate resembles previous papers by Cheeseman and McDermott, leaping from the observation that a speciic application of some AI technology is unable to solve a problem to the conclusion that the technology itself is of limited value. We argue that claims such as this should be made more cautiously in the future, and make constructive sugges...

Libman-Sacks endocarditis is characterized by sterile and verrucous lesions that predominantly affect the aortic and mitral valves. In most cases, patients do not have significant valvular dysfunction. However, patients with significant valvular dysfunction may present with serious complications such as cardiac failure, arrhythmias, and thromboembolic events. Recently, association of Libman-Sac...

(See below for a definition of the Sacks property.) A “definable” variant of this question has been answered in [Sh 480]: Every nontrivial Souslin forcing notion which has the Sacks property has an uncountable antichain. (A Souslin forcing notion is a forcing notion for which the set of conditions, the comparability relation and the incompatibility relation are all analytic subsets of the reals...