A Characterization of Finite Soluble Groups by Laws in Two Variables
School of Mathematical Sciences, Queen Mary, University of London Mile End Rd, London E1 4NS, United Kingdom r.a.wilson{at}qmul.ac.uk, j.n.bray{at}qmul.ac.uk
Mathematical Institute 2429 St Giles', Oxford OX1 3LB, United Kingdom wilsonjs{at}maths.ox.ac.uk
Received 22 August 2003. Revision received 24 February 2004.
Define a sequence (sn) of two-variable words in variables x, y as follows: s0(x, y) = x, sn+1(x,y)=[sn(x, y]y, sn(x,y) for n
0. It is shown that a finite group G is soluble if and only if sn is a law of G for all but finitely many values of n. 2000 Mathematics Subject Classification 20D10, 20D06.