GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
This directory contains a copy of the author's paper A Simple Group Generated by Involutions Interchanging Residue Classes of the Integers. Math. Z. 264 (2010), no. 4, 927-938. http://dx.doi.org/10.1007/s00209-009-0497-8