Could anyone help me with this questions: Find and correct the gap on the proof of the statement 2.3.8 in Robinson's book
3.2.8. Let F be a field and let N be a normal subgroup of SL(n, F) which is not contained in the centre. If either n > 2 or n = 2 and |F|> 3, then N = SL(n, F).
I think on the first part of the proof N contains the commutator $[A,1+E_{1_2}]$ instead of $[A,1+E_{1,n_1+n_2}]$. proof of 3.2.8
