Probabilistic Shoenfield Machines

This article provides the theoretical framework of Probabilistic Shoenfield Machines (PSMs), an extension of the classical Shoenfield Machine that models randomness in the computation process. PSMs are brought in contexts where deterministic computation is insufficient, such as randomized algorithms. By allowing transitions to multiple possible states with certain probabilities, PSMs can solve problems and make decisions based on probabilistic outcomes, hence expanding the variety of possible computations. We provide an overview of PSMs, detailing their formal definitions as well as the computation mechanism and their equivalence with Non-deterministic Shoenfield Machines (NSM).