Declarations

and novelty. The exact random-state average is the Page–Sen result. Exact correction, entanglement breaking, and Stinespring continuity are established theories. The contribution is a complete finite emission realization, a simultaneous leading-history estimate, an exact destructive-record comparison, and a typed separation of entropy and recovery targets. No priority is claimed for the standard theorems.

provenance. Cheung's internal manuscripts are cited by identifier and supplied version. Their documentary comparison does not import their physical models or discharge their unrelated open gates. Hawk05-A is cited as the supplied source file, whose author field is empty; authorship is not inferred. The journal entry for Cheung's Enter article is attributed to the companion's bibliographic record, not represented as an independently verified publisher-status report.

and computational scope. No gravitational Hamiltonian, backreaction equation, physical radiation receiver, island, quantum extremal surface, or realistic microscopic evaporation endpoint is constructed. The prescribed Haar unitary is not compiled over a fixed gate library, and its implementation complexity and cyclic thermodynamic cost are not claimed.

. This source is standalone and written for pdflatex. No successful compiler execution, numerical experiment, proof-assistant verification, independent referee approval, or journal acceptance is asserted.