Hi, All: Could someone please tell me or give me a ref. on the basic properties of Gl(n,R) ; R a ring; possibly a division ring, and Gl(n,R) the group (under composition) of matrices invertible over R ? (I imagine we need a ring R with 1 , to talk about invertibility). I mostly would like to see how the properties of Gl(n,R) are different from those of Gl(n,F) , where F is a field. Thanks.