pub fn is_simple(degree: usize, gens: &[Perm], cap: usize) -> Option<bool>Expand description
Is the group simple — non-trivial with no normal subgroup but {id} and itself? Tested via
conjugacy: every non-trivial normal subgroup contains the whole conjugacy class of any of its elements,
hence the normal closure of that element. So G is simple iff the normal closure of every
non-identity element is all of G. Simple non-abelian groups (e.g. A₅) are exactly the unsolvable
building blocks. None when |G| > cap.