Fitting height and lengths of laws in finite solvable groups

Abstract

Let G be a finite solvable group, and let h(G) denote its Fitting height, namely the length of a shortest normal series in G with nilpotent factors. We show, that any law in G has length at least h(G). This result is then used to improve a previously given bound on the nonsolvable length of finite nonsolvable groups.

we found a gap in the proof of the main result (Theorem B)