2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/59068We show that any birational map between projective hyperKähler manifolds of dimension 4 is composed of a sequence of simple flops or elementary Mukai transformations under the assumption that each irreducible component of the indeterminacy of the birational map is normal.Algebraic Geometrytext