2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/65893We discuss Ray Heitmann's recent proof of the Direct Summand Conjecture in dimension 3 in mixed characteristic. This paper contains a discussion of his methods, a proof of the theorem, and a direct proof of the Canonical Element Conjecture in dimension 3 using his result.Commutative Algebra13C14,13D22text