CFC Minimal Commit Invariant: A Technical Note on State Transition and Unsupported Closure

This technical note presents a minimal state-transition invariant for CFC, a control-layer approach intended to prevent unsupported closure. A candidate state C_t may replace the last verified state V_{t-1} only when the required authorization predicate A_t has been established. The core invariant is: ¬A_t ⇒ ¬Commit(C_t) In the minimal fail-closed update model, if authorization is not established, the previously verified state is preserved rather than silently replaced by an unsupported candidate. The note defines the roles of the last verified state, candidate state, structured difference operator Diff(C_t, V_{t-1}), authorization predicate, and commit operation. It separates candidate generation from authorization to modify verified state, gives a worked example in which UNRESOLVED is preserved when a proposed TRUE state lacks sufficient authorization, and provides minimal implementation pseudocode. The logical implication itself is elementary and is not presented as a claim of mathematical novelty. The contribution of this note is its explicit use as a compact architectural state-control invariant within CFC: candidate generation does not itself authorize state transition. The invariant is intentionally minimal. It does not by itself establish truth, evidence quality, provenance, independence, freshness, scope validity, or completeness. Those properties must be established by the relevant control conditions before authorization is granted.