Subject: message for the list Date: Tue, 13 Apr 2004 13:06:08 +0100 From: "Neil Strickland" To: "Don Davis" A Mathematica representation of some unstable homotopy groups of spheres ------------------------------------------------------------------------ I have just released some new Mathematica programs at http://www.shef.ac.uk/nps/toda/ They are not really finished, but I think they are already useful, and I have moved on to other things for the time being. The idea is that the programs embody most of the results from Toda's book "Composition methods in homotopy groups of spheres" (together with various addenda), so you can ask Mathematica questions (eg 'What is the Hopf invariant of $\epsilon^*_{12}$?' or 'What is the structure of $\pi_{20}S^{10}$' or 'Where does Toda calculate $P(\sigma_{11})$?' or 'What is the genealogy of $\epsilon_3$?' or 'Which cocycle in the lambda algebra represents $\zeta'$?') without rooting around the book for the answer. The framework is reasonably general so results about other homotopy groups or other spaces could easily be added. There is further general discussion at http://www.shef.ac.uk/nps/toda/Toda.pdf I have some hesitation about using Mathematica for this project; it works very well, but the software is expensive and many people do not have it. On the other hand, automatic translation to other formats would probably not be too difficult. If anyone has pressing needs in this direction, they could let me know. I would argue that this kind of program is the best way to distribute the results of intricate calculations. Perhaps people would like to discuss this point of view. Neil