Example. Selecting a historical rollout under a current policy stamp [ftip-0059]
Example. Selecting a historical rollout under a current policy stamp [ftip-0059]
Reusing one historical rollout recomputes current-policy annotations without mutating the stored record.
Let the stored record be \(R=(q,\nu _b,\tau ,e)\) and suppose its behaviour policy assigned the recorded action probability \(0.25\). Under the current stamp the same action has probability \(0.50\), so this attempt records importance ratio \(0.50/0.25=2\). Its age \(3\) and prior-use count \(2\) are also attempt-time metadata; none of these three values rewrites \(R\).
The behaviour/current-policy distinction is required by the reuse analysis in [miao2026when, Section 3]. The finite annotation makes provenance explicit. Statistical safety of ratio \(2\), age \(3\), or a second reuse is left undecided.