Distributed computability: Relating k-immediate snapshot and x-set agreement

This paper introduces a generalization of the immediate snapshot object denoted k-immediate snapshot, requiring that the snapshot returned contains at least (n−k) pairs. The case k=n−1 corresponds to the original immediate snapshot object, which requires that the snapshot returned contains at least one pair 〈process id, value〉 pair, that corresponds to the process id that invoked the operation).