Focusing on trace and testing semantics, this monograph explores nondeterministic and probabilistic processes through simple probabilistic automata. It defines traces as sequences of activities that abstract branching behaviors and formalizes tests as processes with success states. The author reviews nondeterministic and probabilistic models, addressing anomalies and offering solutions. Additionally, alternative characterizations of probabilistic trace equivalences and the challenges of probabilistic testing equivalence are discussed. This work is tailored for researchers in formal methods related to programming languages.
