2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/168767Young's integral inequality is complemented with an upper bound to the remainder. The new inequality turns out to be equivalent to Young's inequality, and the cases in which the equality holds become particularly transparent in the new formulation.5 pages. v2: Title changed to match published version. Previous title: "Doubling Young's inequality"General Mathematics26D10; 44A15text