n. 25B6; noun
proof of ownership : EVIDENCE, verification, corroboration, authentication, confirmation, certification, documentation, validation, attestation, substantiation.
the proofs of a book : PAGE PROOF, galley proof, galley, pull, slip; revise.
25B6; adjective no system is proof against theft : RESISTANT, immune, unaffected, invulnerable, impenetrable, impervious, repellent.