On 5 January 2017 at 09:27, Jeroen Demeyer <jdeme...@cage.ugent.be> wrote: > Sorry, I was wrong. I actually looked at the PARI source code this time and > the warning comes from the bnfisprincipal() function to determine the class > of a given ideal in the class group (so, in particular, it can be used to > check whether an ideal is principal). This function can also compute a > generator of the ideal, but it might fail doing that, giving the warning > message. I believe this does not affect the correctness.
That sounds correct to me too, so thanks for checking the source code. When it determines that an ideal is principal it can reconstruct the generator using some additional information stored which includes logs of elements in the various embeddings (as explained in Henri COhen's second book), and at this point there may not be sufficient precision. As Jeroen says, the correctness of the class number should be affected. > > > -- > 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 post to this group, send email to sage-support@googlegroups.com. > Visit this group at https://groups.google.com/group/sage-support. > For more options, visit https://groups.google.com/d/optout. -- 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 post to this group, send email to sage-support@googlegroups.com. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
