Yes, probably working up to some degree. I do no know if this could help. El El jue, 25 ago 2022 a las 18:09, John H Palmieri <jhpalmier...@gmail.com> escribió:
> One issue is that f-id is not a ring homomorphism. So do I restrict to a > range of degrees, convert to vector spaces, and compute the kernel? I'm not > sure of the right approach. > > On Thursday, August 25, 2022 at 3:11:12 AM UTC-7 pedrito...@gmail.com > wrote: > >> Dear John, >> Wouldn’t be of some help to consider the kernel of f-Id (with Id the >> identity map)? >> Best, >> Pedro >> >> El El jue, 25 ago 2022 a las 8:22, Dima Pasechnik <dim...@gmail.com> >> escribió: >> >>> >>> >>> On Thu, 25 Aug 2022, 00:38 John H Palmieri, <jhpalm...@gmail.com> wrote: >>> >>>> I have a polynomial ring R = k[x1, x2, ..., xn] and a ring homomorphism >>>> f: R -> R. In case it matters, k=GF(2). I would like to find the subring of >>>> elements x satisfying f(x) = x: that is, I want to find the equalizer of >>>> the pair of maps (f, 1). Is there anything in Sage that will compute this? >>>> The more polynomial generators this can handle, the better. >>>> >>> >>> Is this subring finitely generated? Invariant theory in positive >>> characteristic is full of surprises... >>> >>> >>>> -- >>>> John >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "sage-support" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to sage-support...@googlegroups.com. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/sage-support/6b028ddf-d0b7-4156-adad-7315cc6220a1n%40googlegroups.com >>>> <https://groups.google.com/d/msgid/sage-support/6b028ddf-d0b7-4156-adad-7315cc6220a1n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "sage-support" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to sage-support...@googlegroups.com. >>> >> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/sage-support/CAAWYfq3d%3DLMGOoXUyPhqRgzWfcMvrc%3DWZrxOTN7rfBg71VL06Q%40mail.gmail.com >>> <https://groups.google.com/d/msgid/sage-support/CAAWYfq3d%3DLMGOoXUyPhqRgzWfcMvrc%3DWZrxOTN7rfBg71VL06Q%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- > You received this message because you are subscribed to the Google Groups > "sage-support" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-support+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sage-support/8def5bf5-9526-49ee-b280-3203e2dd4949n%40googlegroups.com > <https://groups.google.com/d/msgid/sage-support/8def5bf5-9526-49ee-b280-3203e2dd4949n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/CAOAJP6r569ZoxCwb%3DdpbJgt%2B_grTWV6xdPMOVGqbGjH_9g5T3A%40mail.gmail.com.
