Non-repudiation asks whether an action can be proven to have happened, so that the actor cannot deny it. A measure relates provable actions to the actions in scope. The proof usually rests on a signature, a sealed log or a trusted timestamp, and the measure is about coverage and verifiability. A log that the actor can edit is not non-repudiation evidence. The population is the set of actions where a dispute is plausible: approvals, payments, submissions, deletions. The measure should be tested by trying to deny an action and checking whether the record settles it.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.