Hi Konrad, First of all, thanks to all who worked on https://github.com/billpage/ncpoly. It's always nice to see new research entering FriCAS.
I admit that I haven't followed the fdalg discussion very deeply, but reading your documentation is not very helpful. What is the audience for https://github.com/billpage/ncpoly/blob/master/fdalg_20180907.pdf ? Is Section 2 really relevant if I just want to compute with elements in a free field? Wouldn't I just want to construct some (non-commutative) polynomials and then "divide" them similar to the commutative case. I would think that as a user I first must learn how to get the basic things done before going into detail of how it is implemented. Why not starting with "Let f be the non-commutative polynomial x - x*y*x. In the following we compute its inverse f^(-1)." And then you demonstrate how this can be done and explain how the different parts of the output are to be interpreted. Furthermore, I haven't seen that you ever specified that you write a dot instead of 0 in your matrices. The example f=(x-xyx)^(-1) (on page 2) it would certainly be helpful, if you explained how one constructs the entries of A. At the beginning of page 4 I then read "g_11 : FDA := x+x*y*x". Why now + instead of the - in f? Only a few naive comments... Ralf On 09/17/2018 05:02 AM, Bill Page wrote: > On Fri, Sep 7, 2018 at 12:24 PM Konrad Schrempf wrote: > ... > For Bill: If it helps to support further discussions, please put the > code on github (maybe including the mini-documentation). I guess that > it will take a while to include it in standard FriCAS. Just tell me if > you need a formal declaration for the distribution. > > Is there something important I forgot? Some months ago I just claimed > that FriCAS will be the first computer algebra system being able to > work with elements in the universal field of fractions of a free > associative algebra. Now you can convince yourself. I guess that it > takes a while to get used to working with linear representations > (admissible linear systems). For small polynomials that really looks > like an overkill. But for the example on page 15 one could see the > beauty of Cohn's theory. You should try p_43^-1 ... > > -- > > Documentation: > https://github.com/billpage/ncpoly/blob/master/fdalg_20180907.pdf > > Source code: https://github.com/billpage/ncpoly > > Comments appreciated. > -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
