Li Fuan
Let R be an arbitrary commutative ring, and n be an integer ≥3. It is proved for any ideal J of R that
ESp2n(R,J)=[ESp2n(R), ESp2n(J)]=[ESp2n(R), ESp2n(R,J)] =[ESp2n(R), GSp2n(R,J)]=[Sp2n(R), ESp2n(R,J)].
Furthermore, the problem of normal subgroups of Sp2n(R) has an affirmative solution if and only if aR=a2R+2aR for each a in R. This covers the relevant results of [4], [8], [10], [12] and [13].