2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/216263This paper has been withdrawn by the author since $U$ in Lemma 2 is in general not a subspace.5 pagesCommutative AlgebraOptimization and Control65D32, 30E05, 13P10A Gröbner basis proof of the flat extension theorem for moment matricestext