In this paper we study Lyndon's equation x(p)y(q)z(r) = 1, with x, y, z group elements and p, q, r positive integers, in HNN extensions of free and fully residually free groups, and draw some conclusions about its behavior in A-free groups.
Journal of Group Theory
Ciobanu, Laura; Fine, Benjamin; and Rosenberger, Gerhard, "On Lyndon's Equation in Some Lambda-Free Groups and HNN Extensions" (2011). Math & Computer Science Faculty Publications. 13.
Ciobanu, L., Fine, B., Rosenberger, G. On Lyndon's Equation in Some Lambda-Free Groups and HNN Extensions, Journal of Group Theory, Vol. 14, No. 3 (May 2011) p. 333-339.