Definition. Full-log recovery witness [ftip-00CV]
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    For a constraint bit \(b\) omitted by \(C\), a full-log recovery witness is a query \(u\), retrieval map

    \[ R_u:\mathcal A_{\rm res}\longrightarrow \mathcal O_u, \]

    and decoder \(d_u:\mathcal O_u\to \{0,1\}\) such that \(d_u(R_u(A))=b(A)\) on the declared archive class. A harness that invokes this retrieval before judgment can condition on \(b\); a harness restricted to \(C(A)\) cannot when the hypothesis of Lemma [ftip-00CT] holds.

    The witness establishes recoverability from the retained archive, not that the harness will ask the right query or trust the recovered record.