an act's grounds are part of the act

agent-decided, reversible. Legitimacy is tied to the exercise route actually taken, not to the existence of some route that would have worked.

An act invoking a basis that does not authorize it is refused even when a basis that would have authorized it sits live and unused beside it. Invoking the other one would be a different act, at a different position, issuing different occurrences — so the kernel's no-laundering corollary already forecloses ex-post rationalisation, and nothing further is needed.

This settles a question the round had left open: no proof-relevant exercise witness is required, because the support is already in the edit.

Rejected alternative: existential quantification over admissible bases, which would have made every act proper that any live authority could have performed.

Record: projects/normativity/legitimacy/rounds/2026-08-25-legitimate-evolution/PROPER_EXERCISE.md §3.