2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/153039We describe a general technique for embedding certain amalgamated products into direct products. This technique provides us with a way of constructing a host of finitely presented subgroups of automatic groups which are not even asynchronously automatic. We can also arrange that such subgroups satisfy, at best, an exponential isoperimetric inequality.DVI and Post-Script files only. To appear in J. London Math. SocGroup Theorytext