set |S> => |a> + |b> + |c1> + |d> + |e> + |f1>
set |a> => |a1> + |a2> + |a3>
set |b> => |b1> + |b2>
set |c1> => |c1>
set |d> => |d1>
set |e> => |e1> + |e2> + |e3> + |e4>
set |f1> => |f1>