A nilpotence theorem for modules over the mod 2 Steenrod algebra
Michael J. Hopkins and John H. Palmieri

4 September 1992

Abstract
  We prove that the mod 2 Steenrod algebra A satisfies the "detection" 
property; i.e., every non-nilpotent element of Ext_A (F_2;F_2) can
be detected by restricting to an exterior sub-Hopf algebra of A.