In this paper we study the relative succinctness of different representations of polymomial time languages and investigate what can and cannot be formally verified about these representations. We also show that the relative succintness of different representations of languages is directly related to the separation of the corresponding complexity classes; for example, PTIME $\neq$ NPTIME if and only if the relative succintness of representing languages in PTIME by deterministic and nondeterministic clocked polynomial time machines is not recursively bound which happens if and only if the relative succintness of these representations is not linearly bounded.