Attained prefixes of honest hiding and reading outcomes #
The honest register matrices already vanish outside the image of the relevant CL computation. These lemmas expose that support on whole operators and on the complete parsed-answer alphabet, so executable prefix scans may reject unattained claims without changing honest measurements.
A nonzero honest Hide outcome reports an actual output after exactly k stages.
Every earlier prefix of a nonzero honest Hide claim is attained by the same seed.
A nonzero honest Read outcome reports an actual complete CL output.
Every prefix of a nonzero honest Read claim is attained, including ℓ - 1.
Tensoring with the source identity does not create unattained Hide labels.
Tensoring with the source answer effect does not create unattained Read labels.
Every nonzero honest auxiliary effect passes the local prefix guard. The claim includes every parsed label, so no format promise is needed.