2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/59597We present an example which confirms the assertion of the title.16p. (to appear in Ann. Inst. Fourier)Algebraic GeometryCommutative Algebra13A02 (Primary) 13F20 (Secondary)Miyanishi's characterization of the affine 3-space does not hold in higher dimensionstext