I lied slightly in my recent note about direct factors. To determine
whether a subgroup H of G is a direct factor, one should, of course,
first check that <H,Centralizer(G,H)> = G before looking for comple-
mentary direct factors with Complement(Centralizer(G,H),Centre(H)).
--

 _--_|\           C.R.B. Wright
/      \          Charles.Wright@maths.anu.edu.au
\_.--._/          wright@math.uoregon.edu
      v