Products of involutions in simple Chevalley groups (Q1841862)

Let \(G\) be a Chevalley group defined over a field \(K\). If \(K\) has enough elements, then every element of \(G\) is a product of five or fewer elements, and for the non-central elements, four involutions suffice. The monomial subgroup \(N\) of \(G\) is generated by involutions, provided that \(G\) is not of type \(C_r\) or \(B_2\).