B.5.MPC.R:4.3 - Locate the incompatibility without guessing its cause

Work a small instance or derive a consequence that distinguishes the competing accounts. If a command is outside the admitted range, its value and range already establish that incompatibility. If two physical inputs produce the same represented data but require different answers, exhibit those two inputs and their common representation.

When several explanations remain, compare what each would require you to change. A motion discrepancy might come from calibration, a retained command or an incorrectly interpreted position. Recover an available observation that distinguishes those accounts, or choose a worthwhile further observation through C.11.DUA. An investigation is unnecessary when a sufficient bound or conditional answer already settles the present decision.

Account for what the observation does. Identify which processes continue during measurement or debugging, which input remains applied and which state is changed by the probe. Use A.3.3 for the state and C.16 for the measurement relation when that construction is unresolved.

A mathematical account may support several physical interpretations. Compare their additional physical assumptions and the observations or interventions that distinguish them. Retain an unresolved difference when the available observations do not decide it; use the consequences shared by those interpretations when they suffice.