2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/98502We include short and elementary proofs of two theorems characterizing reductive group schemes over a discrete valuation ring, in a slightly more general context.10 pages. To appear in C. E. J. MNumber TheoryRepresentation Theory11G10, 11G18, 14F30, 14G35, 14G40, 14K10, and 14J10text