Suppose that 
(the commuting product of all components of 
) is simple and 
contains a semisimple group
involution. Then there is some semisimple group
involution 
such that 
has a normal subgroup 
which is either quasisimple or isomorphic
to 
and such that 
is tightly embedded.
Aschbacher's Component Theorem
See also
Group Involution, Isomorphic Groups, Normal Subgroup, Quasisimple Group, Simple Group, Tightly EmbeddedExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Aschbacher's Component Theorem." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/AschbachersComponentTheorem.html