Release and conclusion

to the motivating question. Under complete unitary evolution, an unknown quantum state is not annihilated: the complete channel has a reference-preserving inverse on its encoded range. That is the proved mathematical principle.

The black-hole information problem asks whether a correct physical evaporation model supplies such a complete evolution and whether its outgoing radiation is the output from which the code can be recovered. Those are not consequences of the phrase “unitary evolution” alone.

and evidence boundary. This is a self-contained analytical manuscript source. A successful pdflatex build, independently executed numerical certificate, formal proof check, independent technical review, and journal acceptance are not asserted. The author should confirm metadata and archival availability of unpublished comparisons before submission. The familiar preservation and no-hiding principles are attributed to their established literature; no priority claim is made.