Dear Forum, This is to announce the release of RCWA 1.5.
The RCWA package provides methods for computing in certain infinite permutation groups acting on the integers. Due to a change of maintainership of the GAP website it may take some time until the new version is available at the usual location http://www.gap-system.org/Packages/rcwa.html. In any case, you can get RCWA 1.5 from http://www.cip.mathematik.uni-stuttgart.de/~kohlsn/rcwa.html . Let me take the opportunity to point to a related recent preprint of mine: ---------------------------------------------------------------------------- Title: Three Countable Highly Transitive Simple Groups Containing Collatz' Permutation Abstract: We construct three countable simple permutation groups which act highly transitively on N_0 resp. Z. These groups form an ascending chain w.r.t. inclusion. The smallest of them is generated by involutions which interchange two disjoint residue classes, each. The free group of rank 2 and the modular group PSL(2,Z) embed in this group. We show by means of computation that it further contains a certain permutation of the integers which has already been investigated by Lothar Collatz in 1932, and whose cycle structure is unknown so far. http://www.cip.mathematik.uni-stuttgart.de/~kohlsn/preprints/simplegp.pdf ---------------------------------------------------------------------------- Wishing you fun and success using RCWA, Stefan Kohl _______________________________________________ Forum mailing list [email protected] http://mail.gap-system.org/mailman/listinfo/forum
