Before revision: The modular subset sum problem consists of deciding, given a modulus m, a multiset S of n integers in 0.. m , and a target integer t, whether there exists a subset of S with elements summing to t \mod  , and to report such a set if it exists.
After revision: The modular subset sum problem consists of deciding, given a modulus m, a multiset S of n integers in 0.. m-1 , and a target integer t, whether there exists a subset of S with elements summing to t \mod , and to report such a set if it exists.