 E. C. Zeeman modified Stalling's construction to work in dimensions 5 and 6.In 1962, Smale proved a PL homotopy "n"-sphere was PL-isomorphic to the standard PL "n"-sphere for "n" at least 5.In 1966, M. H. A. Newman extended PL engulfing to the topological situation and proved that for formula_3 a "topological" homotopy "n"-sphere is homeomorphic to the "n"-sphere.