Commutators spanning the matrices

hkus10
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Let T be the set of all matrics of the form AB - BA, where A and B are nxn matrics. Show that span T is not Mnn.

1) does "span T is not Mnn" mean that Mnn does not span T?

Thanks
 
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Looks to me like what it means is that T does not span Mnn, not the other way around.
 
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