2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/100086A concise presentation of Schrodinger's ancilla theorem (1936 Proc. Camb. Phil. Soc. 32, 446) and its several recent rediscoveries.v3: Improvements in proofs of Lemma and parts (b) and (e) of the Theorem. Added to Discussion. As published in Found Phys LettQuantum Physicstext