><^
Date: Fri, 15 Jan 1993 12:22:56 +0100 ><^
From: Dave L. Johnson <dlj@maths.nott.ac.uk> <^
Subject: Re: a question to HNN extensions
Dear Gap-forum,
especially Toni. Yes, this is correct. The stable letter in an HNN-extension
appears with exponent-sum zero in every relator and so has infinite order
even in the abelianised group.