One update to what I wrote before. In J. P. Bell, A. Heinle, and V. Levandovskyy, On Noncommutative Finite Factorization Domains, Trans. Amer. Math. Soc. 369 (2017), 2675-2695
there is proof of finite number of factorizations. I have now implemented the lift part of Davenport-Caruso method. You fetch code at: http://www.math.uni.wroc.pl/~hebisch/fricas/dcfact2.input http://www.math.uni.wroc.pl/~hebisch/fricas/nc_ini04c.input As before, dcfact2.input is an actual routine, nc_ini04c.input set up needed types. You can try things like: dc_fact(((x*z - z*x)^2 - 2)*((x*z - z*x)^2 - 3)*((x*z - z*x)^2 - 5)) The idea is like in Caruso preprint, but code differs -- I coded what follows by working out solutions to lift equations. The code is unoptimized, for example for homogeneous polynomials it runs the whole lift, while we know that the factorization must be homogeneous... Also, code introduces extra parameters when there is overlap between leading monomials of top factors, while in many cases this parameter could be immediately eliminated. Still, it seem to work quite a bit faster than xdpolyf1.spad. -- Waldek Hebisch -- 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 fricas-devel+unsubscr...@googlegroups.com. To post to this group, send email to fricas-devel@googlegroups.com. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
