Delporte-Gallet, CaroleFauconnier, HuguesGuerraoui, RachidTielmann, Andreas2008-08-072008-08-072008-08-07200810.1007/978-3-540-87779-0_8https://infoscience.epfl.ch/handle/20.500.14299/27268In the set-agreement problem, n processes seek to agree on at most n−1 different values. This paper determines the weakest failure detector to solve this problem in a message-passing system where processes may fail by crashing. This failure detector, called the Loneliness detector and denoted L, outputs one of two values, “true” or “false” such that: (1) there is at least one process where L outputs always “false”, and (2) if only one process is correct, L eventually outputs “true” at this process.text::conference output::conference proceedings::conference paper